diff --git a/session/sess_cookie.go b/session/sess_cookie.go
index 7962be18..ddf1a902 100644
--- a/session/sess_cookie.go
+++ b/session/sess_cookie.go
@@ -11,12 +11,15 @@ import (
 
 var cookiepder = &CookieProvider{}
 
+// Cookie SessionStore
 type CookieSessionStore struct {
 	sid    string
-	values map[interface{}]interface{} //session data
+	values map[interface{}]interface{} // session data
 	lock   sync.RWMutex
 }
 
+// Set value to cookie session.
+// the value are encoded as gob with hash block string.
 func (st *CookieSessionStore) Set(key, value interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -24,6 +27,7 @@ func (st *CookieSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// Get value from cookie session
 func (st *CookieSessionStore) Get(key interface{}) interface{} {
 	st.lock.RLock()
 	defer st.lock.RUnlock()
@@ -35,6 +39,7 @@ func (st *CookieSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// Delete value in cookie session
 func (st *CookieSessionStore) Delete(key interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -42,6 +47,7 @@ func (st *CookieSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// Clean all values in cookie session
 func (st *CookieSessionStore) Flush() error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -49,10 +55,12 @@ func (st *CookieSessionStore) Flush() error {
 	return nil
 }
 
+// Return id of this cookie session
 func (st *CookieSessionStore) SessionID() string {
 	return st.sid
 }
 
+// Write cookie session to http response cookie
 func (st *CookieSessionStore) SessionRelease(w http.ResponseWriter) {
 	str, err := encodeCookie(cookiepder.block,
 		cookiepder.config.SecurityKey,
@@ -79,12 +87,21 @@ type cookieConfig struct {
 	Maxage       int    `json:"maxage"`
 }
 
+// Cookie session provider
 type CookieProvider struct {
 	maxlifetime int64
 	config      *cookieConfig
 	block       cipher.Block
 }
 
+// Init cookie session provider with max lifetime and config json.
+// maxlifetime is ignored.
+// json config:
+// 	securityKey - hash string
+// 	blockKey - gob encode hash string. it's saved as aes crypto.
+// 	securityName - recognized name in encoded cookie string
+// 	cookieName - cookie name
+// 	maxage - cookie max life time.
 func (pder *CookieProvider) SessionInit(maxlifetime int64, config string) error {
 	pder.config = &cookieConfig{}
 	err := json.Unmarshal([]byte(config), pder.config)
@@ -104,6 +121,8 @@ func (pder *CookieProvider) SessionInit(maxlifetime int64, config string) error
 	return nil
 }
 
+// Get SessionStore in cooke.
+// decode cooke string to map and put into SessionStore with sid.
 func (pder *CookieProvider) SessionRead(sid string) (SessionStore, error) {
 	maps, _ := decodeCookie(pder.block,
 		pder.config.SecurityKey,
@@ -116,26 +135,32 @@ func (pder *CookieProvider) SessionRead(sid string) (SessionStore, error) {
 	return rs, nil
 }
 
+// Cookie session is always existed
 func (pder *CookieProvider) SessionExist(sid string) bool {
 	return true
 }
 
+// Implement method, no used.
 func (pder *CookieProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	return nil, nil
 }
 
+// Implement method, no used.
 func (pder *CookieProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// Implement method, no used.
 func (pder *CookieProvider) SessionGC() {
 	return
 }
 
+// Implement method, return 0.
 func (pder *CookieProvider) SessionAll() int {
 	return 0
 }
 
+// Implement method, no used.
 func (pder *CookieProvider) SessionUpdate(sid string) error {
 	return nil
 }
diff --git a/session/sess_file.go b/session/sess_file.go
index 5d33d0e2..73eec874 100644
--- a/session/sess_file.go
+++ b/session/sess_file.go
@@ -18,6 +18,7 @@ var (
 	gcmaxlifetime int64
 )
 
+// File session store
 type FileSessionStore struct {
 	f      *os.File
 	sid    string
@@ -25,6 +26,7 @@ type FileSessionStore struct {
 	values map[interface{}]interface{}
 }
 
+// Set value to file session
 func (fs *FileSessionStore) Set(key, value interface{}) error {
 	fs.lock.Lock()
 	defer fs.lock.Unlock()
@@ -32,6 +34,7 @@ func (fs *FileSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// Get value from file session
 func (fs *FileSessionStore) Get(key interface{}) interface{} {
 	fs.lock.RLock()
 	defer fs.lock.RUnlock()
@@ -43,6 +46,7 @@ func (fs *FileSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// Delete value in file session by given key
 func (fs *FileSessionStore) Delete(key interface{}) error {
 	fs.lock.Lock()
 	defer fs.lock.Unlock()
@@ -50,6 +54,7 @@ func (fs *FileSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// Clean all values in file session
 func (fs *FileSessionStore) Flush() error {
 	fs.lock.Lock()
 	defer fs.lock.Unlock()
@@ -57,10 +62,12 @@ func (fs *FileSessionStore) Flush() error {
 	return nil
 }
 
+// Get file session store id
 func (fs *FileSessionStore) SessionID() string {
 	return fs.sid
 }
 
+// Write file session to local file with Gob string
 func (fs *FileSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer fs.f.Close()
 	b, err := encodeGob(fs.values)
@@ -72,17 +79,23 @@ func (fs *FileSessionStore) SessionRelease(w http.ResponseWriter) {
 	fs.f.Write(b)
 }
 
+// File session provider
 type FileProvider struct {
 	maxlifetime int64
 	savePath    string
 }
 
+// Init file session provider.
+// savePath sets the session files path.
 func (fp *FileProvider) SessionInit(maxlifetime int64, savePath string) error {
 	fp.maxlifetime = maxlifetime
 	fp.savePath = savePath
 	return nil
 }
 
+// Read file session by sid.
+// if file is not exist, create it.
+// the file path is generated from sid string.
 func (fp *FileProvider) SessionRead(sid string) (SessionStore, error) {
 	err := os.MkdirAll(path.Join(fp.savePath, string(sid[0]), string(sid[1])), 0777)
 	if err != nil {
@@ -117,6 +130,8 @@ func (fp *FileProvider) SessionRead(sid string) (SessionStore, error) {
 	return ss, nil
 }
 
+// Check file session exist.
+// it checkes the file named from sid exist or not.
 func (fp *FileProvider) SessionExist(sid string) bool {
 	_, err := os.Stat(path.Join(fp.savePath, string(sid[0]), string(sid[1]), sid))
 	if err == nil {
@@ -126,16 +141,20 @@ func (fp *FileProvider) SessionExist(sid string) bool {
 	}
 }
 
+// Remove all files in this save path
 func (fp *FileProvider) SessionDestroy(sid string) error {
 	os.Remove(path.Join(fp.savePath))
 	return nil
 }
 
+// Recycle files in save path
 func (fp *FileProvider) SessionGC() {
 	gcmaxlifetime = fp.maxlifetime
 	filepath.Walk(fp.savePath, gcpath)
 }
 
+// Get active file session number.
+// it walks save path to count files.
 func (fp *FileProvider) SessionAll() int {
 	a := &activeSession{}
 	err := filepath.Walk(fp.savePath, func(path string, f os.FileInfo, err error) error {
@@ -148,6 +167,8 @@ func (fp *FileProvider) SessionAll() int {
 	return a.total
 }
 
+// Generate new sid for file session.
+// it delete old file and create new file named from new sid.
 func (fp *FileProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	err := os.MkdirAll(path.Join(fp.savePath, string(oldsid[0]), string(oldsid[1])), 0777)
 	if err != nil {
@@ -197,6 +218,7 @@ func (fp *FileProvider) SessionRegenerate(oldsid, sid string) (SessionStore, err
 	return ss, nil
 }
 
+// remove file in save path if expired
 func gcpath(path string, info os.FileInfo, err error) error {
 	if err != nil {
 		return err
diff --git a/session/sess_mem.go b/session/sess_mem.go
index c74c2602..33c84717 100644
--- a/session/sess_mem.go
+++ b/session/sess_mem.go
@@ -9,6 +9,8 @@ import (
 
 var mempder = &MemProvider{list: list.New(), sessions: make(map[string]*list.Element)}
 
+// memory session store.
+// it saved sessions in a map in memory.
 type MemSessionStore struct {
 	sid          string                      //session id
 	timeAccessed time.Time                   //last access time
@@ -16,6 +18,7 @@ type MemSessionStore struct {
 	lock         sync.RWMutex
 }
 
+// set value to memory session
 func (st *MemSessionStore) Set(key, value interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -23,6 +26,7 @@ func (st *MemSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value from memory session by key
 func (st *MemSessionStore) Get(key interface{}) interface{} {
 	st.lock.RLock()
 	defer st.lock.RUnlock()
@@ -34,6 +38,7 @@ func (st *MemSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete in memory session by key
 func (st *MemSessionStore) Delete(key interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -41,6 +46,7 @@ func (st *MemSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in memory session
 func (st *MemSessionStore) Flush() error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -48,27 +54,31 @@ func (st *MemSessionStore) Flush() error {
 	return nil
 }
 
+// get this id of memory session store
 func (st *MemSessionStore) SessionID() string {
 	return st.sid
 }
 
+// Implement method, no used.
 func (st *MemSessionStore) SessionRelease(w http.ResponseWriter) {
 }
 
 type MemProvider struct {
-	lock        sync.RWMutex             //用来锁
-	sessions    map[string]*list.Element //用来存储在内存
-	list        *list.List               //用来做gc
+	lock        sync.RWMutex             // locker
+	sessions    map[string]*list.Element // map in memory
+	list        *list.List               // for gc
 	maxlifetime int64
 	savePath    string
 }
 
+// init memory session
 func (pder *MemProvider) SessionInit(maxlifetime int64, savePath string) error {
 	pder.maxlifetime = maxlifetime
 	pder.savePath = savePath
 	return nil
 }
 
+// get memory session store by sid
 func (pder *MemProvider) SessionRead(sid string) (SessionStore, error) {
 	pder.lock.RLock()
 	if element, ok := pder.sessions[sid]; ok {
@@ -87,6 +97,7 @@ func (pder *MemProvider) SessionRead(sid string) (SessionStore, error) {
 	return nil, nil
 }
 
+// check session store exist in memory session by sid
 func (pder *MemProvider) SessionExist(sid string) bool {
 	pder.lock.RLock()
 	defer pder.lock.RUnlock()
@@ -97,6 +108,7 @@ func (pder *MemProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for session store in memory session
 func (pder *MemProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	pder.lock.RLock()
 	if element, ok := pder.sessions[oldsid]; ok {
@@ -120,6 +132,7 @@ func (pder *MemProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return nil, nil
 }
 
+// delete session store in memory session by id
 func (pder *MemProvider) SessionDestroy(sid string) error {
 	pder.lock.Lock()
 	defer pder.lock.Unlock()
@@ -131,6 +144,7 @@ func (pder *MemProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// clean expired session stores in memory session
 func (pder *MemProvider) SessionGC() {
 	pder.lock.RLock()
 	for {
@@ -152,10 +166,12 @@ func (pder *MemProvider) SessionGC() {
 	pder.lock.RUnlock()
 }
 
+// get count number of memory session
 func (pder *MemProvider) SessionAll() int {
 	return pder.list.Len()
 }
 
+// expand time of session store by id in memory session
 func (pder *MemProvider) SessionUpdate(sid string) error {
 	pder.lock.Lock()
 	defer pder.lock.Unlock()
diff --git a/session/sess_mysql.go b/session/sess_mysql.go
index 7bad9e4a..b471c6c0 100644
--- a/session/sess_mysql.go
+++ b/session/sess_mysql.go
@@ -1,11 +1,12 @@
 package session
 
-//CREATE TABLE `session` (
-//  `session_key` char(64) NOT NULL,
-//  `session_data` blob,
-//  `session_expiry` int(11) unsigned NOT NULL,
-//  PRIMARY KEY (`session_key`)
-//) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+// mysql session support need create table as sql:
+//	CREATE TABLE `session` (
+//	`session_key` char(64) NOT NULL,
+//	session_data` blob,
+//	`session_expiry` int(11) unsigned NOT NULL,
+//	PRIMARY KEY (`session_key`)
+//	) ENGINE=MyISAM DEFAULT CHARSET=utf8;
 
 import (
 	"database/sql"
@@ -18,6 +19,7 @@ import (
 
 var mysqlpder = &MysqlProvider{}
 
+// mysql session store
 type MysqlSessionStore struct {
 	c      *sql.DB
 	sid    string
@@ -25,6 +27,8 @@ type MysqlSessionStore struct {
 	values map[interface{}]interface{}
 }
 
+// set value in mysql session.
+// it is temp value in map.
 func (st *MysqlSessionStore) Set(key, value interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -32,6 +36,7 @@ func (st *MysqlSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value from mysql session
 func (st *MysqlSessionStore) Get(key interface{}) interface{} {
 	st.lock.RLock()
 	defer st.lock.RUnlock()
@@ -43,6 +48,7 @@ func (st *MysqlSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete value in mysql session
 func (st *MysqlSessionStore) Delete(key interface{}) error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -50,6 +56,7 @@ func (st *MysqlSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in mysql session
 func (st *MysqlSessionStore) Flush() error {
 	st.lock.Lock()
 	defer st.lock.Unlock()
@@ -57,10 +64,13 @@ func (st *MysqlSessionStore) Flush() error {
 	return nil
 }
 
+// get session id of this mysql session store
 func (st *MysqlSessionStore) SessionID() string {
 	return st.sid
 }
 
+// save mysql session values to database.
+// must call this method to save values to database.
 func (st *MysqlSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer st.c.Close()
 	b, err := encodeGob(st.values)
@@ -72,11 +82,13 @@ func (st *MysqlSessionStore) SessionRelease(w http.ResponseWriter) {
 
 }
 
+// mysql session provider
 type MysqlProvider struct {
 	maxlifetime int64
 	savePath    string
 }
 
+// connect to mysql
 func (mp *MysqlProvider) connectInit() *sql.DB {
 	db, e := sql.Open("mysql", mp.savePath)
 	if e != nil {
@@ -85,12 +97,15 @@ func (mp *MysqlProvider) connectInit() *sql.DB {
 	return db
 }
 
+// init mysql session.
+// savepath is the connection string of mysql.
 func (mp *MysqlProvider) SessionInit(maxlifetime int64, savePath string) error {
 	mp.maxlifetime = maxlifetime
 	mp.savePath = savePath
 	return nil
 }
 
+// get mysql session by sid
 func (mp *MysqlProvider) SessionRead(sid string) (SessionStore, error) {
 	c := mp.connectInit()
 	row := c.QueryRow("select session_data from session where session_key=?", sid)
@@ -113,6 +128,7 @@ func (mp *MysqlProvider) SessionRead(sid string) (SessionStore, error) {
 	return rs, nil
 }
 
+// check mysql session exist
 func (mp *MysqlProvider) SessionExist(sid string) bool {
 	c := mp.connectInit()
 	defer c.Close()
@@ -126,6 +142,7 @@ func (mp *MysqlProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for mysql session
 func (mp *MysqlProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	c := mp.connectInit()
 	row := c.QueryRow("select session_data from session where session_key=?", oldsid)
@@ -148,6 +165,7 @@ func (mp *MysqlProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return rs, nil
 }
 
+// delete mysql session by sid
 func (mp *MysqlProvider) SessionDestroy(sid string) error {
 	c := mp.connectInit()
 	c.Exec("DELETE FROM session where session_key=?", sid)
@@ -155,6 +173,7 @@ func (mp *MysqlProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// delete expired values in mysql session
 func (mp *MysqlProvider) SessionGC() {
 	c := mp.connectInit()
 	c.Exec("DELETE from session where session_expiry < ?", time.Now().Unix()-mp.maxlifetime)
@@ -162,6 +181,7 @@ func (mp *MysqlProvider) SessionGC() {
 	return
 }
 
+// count values in mysql session
 func (mp *MysqlProvider) SessionAll() int {
 	c := mp.connectInit()
 	defer c.Close()
diff --git a/session/sess_redis.go b/session/sess_redis.go
index b05e4831..3c51b793 100644
--- a/session/sess_redis.go
+++ b/session/sess_redis.go
@@ -11,10 +11,12 @@ import (
 
 var redispder = &RedisProvider{}
 
+// redis max pool size
 var MAX_POOL_SIZE = 100
 
 var redisPool chan redis.Conn
 
+// redis session store
 type RedisSessionStore struct {
 	p           *redis.Pool
 	sid         string
@@ -23,6 +25,7 @@ type RedisSessionStore struct {
 	maxlifetime int64
 }
 
+// set value in redis session
 func (rs *RedisSessionStore) Set(key, value interface{}) error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -30,6 +33,7 @@ func (rs *RedisSessionStore) Set(key, value interface{}) error {
 	return nil
 }
 
+// get value in redis session
 func (rs *RedisSessionStore) Get(key interface{}) interface{} {
 	rs.lock.RLock()
 	defer rs.lock.RUnlock()
@@ -41,6 +45,7 @@ func (rs *RedisSessionStore) Get(key interface{}) interface{} {
 	return nil
 }
 
+// delete value in redis session
 func (rs *RedisSessionStore) Delete(key interface{}) error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -48,6 +53,7 @@ func (rs *RedisSessionStore) Delete(key interface{}) error {
 	return nil
 }
 
+// clear all values in redis session
 func (rs *RedisSessionStore) Flush() error {
 	rs.lock.Lock()
 	defer rs.lock.Unlock()
@@ -55,10 +61,12 @@ func (rs *RedisSessionStore) Flush() error {
 	return nil
 }
 
+// get redis session id
 func (rs *RedisSessionStore) SessionID() string {
 	return rs.sid
 }
 
+// save session values to redis
 func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	c := rs.p.Get()
 	defer c.Close()
@@ -77,6 +85,7 @@ func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	c.Do("SET", rs.sid, string(b), "EX", rs.maxlifetime)
 }
 
+// redis session provider
 type RedisProvider struct {
 	maxlifetime int64
 	savePath    string
@@ -85,8 +94,9 @@ type RedisProvider struct {
 	poollist    *redis.Pool
 }
 
-//savepath like redisserveraddr,poolsize,password
-//127.0.0.1:6379,100,astaxie
+// init redis session
+// savepath like redis server addr,pool size,password
+// e.g. 127.0.0.1:6379,100,astaxie
 func (rp *RedisProvider) SessionInit(maxlifetime int64, savePath string) error {
 	rp.maxlifetime = maxlifetime
 	configs := strings.Split(savePath, ",")
@@ -122,6 +132,7 @@ func (rp *RedisProvider) SessionInit(maxlifetime int64, savePath string) error {
 	return nil
 }
 
+// read redis session by sid
 func (rp *RedisProvider) SessionRead(sid string) (SessionStore, error) {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -141,6 +152,7 @@ func (rp *RedisProvider) SessionRead(sid string) (SessionStore, error) {
 	return rs, nil
 }
 
+// check redis session exist by sid
 func (rp *RedisProvider) SessionExist(sid string) bool {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -152,6 +164,7 @@ func (rp *RedisProvider) SessionExist(sid string) bool {
 	}
 }
 
+// generate new sid for redis session
 func (rp *RedisProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -181,6 +194,7 @@ func (rp *RedisProvider) SessionRegenerate(oldsid, sid string) (SessionStore, er
 	return rs, nil
 }
 
+// delete redis session by id
 func (rp *RedisProvider) SessionDestroy(sid string) error {
 	c := rp.poollist.Get()
 	defer c.Close()
@@ -189,11 +203,12 @@ func (rp *RedisProvider) SessionDestroy(sid string) error {
 	return nil
 }
 
+// Impelment method, no used.
 func (rp *RedisProvider) SessionGC() {
 	return
 }
 
-//@todo
+// @todo
 func (rp *RedisProvider) SessionAll() int {
 	return 0
 }
diff --git a/session/session.go b/session/session.go
index f41ba85b..d1a44538 100644
--- a/session/session.go
+++ b/session/session.go
@@ -14,6 +14,7 @@ import (
 	"time"
 )
 
+// SessionStore contains all data for one session process with specific id.
 type SessionStore interface {
 	Set(key, value interface{}) error     //set session value
 	Get(key interface{}) interface{}      //get session value
@@ -23,6 +24,8 @@ type SessionStore interface {
 	Flush() error                         //delete all data
 }
 
+// Provider contains global session methods and saved SessionStores.
+// it can operate a SessionStore by its id.
 type Provider interface {
 	SessionInit(gclifetime int64, config string) error
 	SessionRead(sid string) (SessionStore, error)
@@ -61,16 +64,24 @@ type managerConfig struct {
 	ProviderConfig    string `json:"providerConfig"`
 }
 
+// Manager contains Provider and its configuration.
 type Manager struct {
 	provider Provider
 	config   *managerConfig
 }
 
-//options
-//1. is https  default false
-//2. hashfunc  default sha1
-//3. hashkey default beegosessionkey
-//4. maxage default is none
+// Create new Manager with provider name and json config string.
+// provider name:
+// 1. cookie
+// 2. file
+// 3. memory
+// 4. redis
+// 5. mysql
+// json config:
+// 1. is https  default false
+// 2. hashfunc  default sha1
+// 3. hashkey default beegosessionkey
+// 4. maxage default is none
 func NewManager(provideName, config string) (*Manager, error) {
 	provider, ok := provides[provideName]
 	if !ok {
@@ -102,7 +113,8 @@ func NewManager(provideName, config string) (*Manager, error) {
 	}, nil
 }
 
-//get Session
+// Start session. generate or read the session id from http request.
+// if session id exists, return SessionStore with this id.
 func (manager *Manager) SessionStart(w http.ResponseWriter, r *http.Request) (session SessionStore) {
 	cookie, err := r.Cookie(manager.config.CookieName)
 	if err != nil || cookie.Value == "" {
@@ -144,7 +156,7 @@ func (manager *Manager) SessionStart(w http.ResponseWriter, r *http.Request) (se
 	return
 }
 
-//Destroy sessionid
+// Destroy session by its id in http request cookie.
 func (manager *Manager) SessionDestroy(w http.ResponseWriter, r *http.Request) {
 	cookie, err := r.Cookie(manager.config.CookieName)
 	if err != nil || cookie.Value == "" {
@@ -161,16 +173,20 @@ func (manager *Manager) SessionDestroy(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// Get SessionStore by its id.
 func (manager *Manager) GetProvider(sid string) (sessions SessionStore, err error) {
 	sessions, err = manager.provider.SessionRead(sid)
 	return
 }
 
+// Start session gc process.
+// it can do gc in times after gc lifetime.
 func (manager *Manager) GC() {
 	manager.provider.SessionGC()
 	time.AfterFunc(time.Duration(manager.config.Gclifetime)*time.Second, func() { manager.GC() })
 }
 
+// Regenerate a session id for this SessionStore who's id is saving in http request.
 func (manager *Manager) SessionRegenerateId(w http.ResponseWriter, r *http.Request) (session SessionStore) {
 	sid := manager.sessionId(r)
 	cookie, err := r.Cookie(manager.config.CookieName)
@@ -198,20 +214,23 @@ func (manager *Manager) SessionRegenerateId(w http.ResponseWriter, r *http.Reque
 	return
 }
 
+// Get all active sessions count number.
 func (manager *Manager) GetActiveSession() int {
 	return manager.provider.SessionAll()
 }
 
+// Set hash function for generating session id.
 func (manager *Manager) SetHashFunc(hasfunc, hashkey string) {
 	manager.config.SessionIDHashFunc = hasfunc
 	manager.config.SessionIDHashKey = hashkey
 }
 
+// Set cookie with https.
 func (manager *Manager) SetSecure(secure bool) {
 	manager.config.Secure = secure
 }
 
-//remote_addr cruunixnano randdata
+// generate session id with rand string, unix nano time, remote addr by hash function.
 func (manager *Manager) sessionId(r *http.Request) (sid string) {
 	bs := make([]byte, 24)
 	if _, err := io.ReadFull(rand.Reader, bs); err != nil {
diff --git a/toolbox/debug.go b/toolbox/debug.go
index 7cb9db4e..c22af04f 100644
--- a/toolbox/debug.go
+++ b/toolbox/debug.go
@@ -29,16 +29,13 @@ type pointerInfo struct {
 	used []int
 }
 
-//
 // print the data in console
-//
 func Display(data ...interface{}) {
 	display(true, data...)
 }
 
-//
-// return string
-//
+
+// return data print string
 func GetDisplayString(data ...interface{}) string {
 	return display(false, data...)
 }
@@ -67,9 +64,7 @@ func display(displayed bool, data ...interface{}) string {
 	return buf.String()
 }
 
-//
-// return fomateinfo
-//
+// return data dump and format bytes
 func fomateinfo(headlen int, data ...interface{}) []byte {
 	var buf = new(bytes.Buffer)
 
@@ -108,6 +103,7 @@ func fomateinfo(headlen int, data ...interface{}) []byte {
 	return buf.Bytes()
 }
 
+// check data is golang basic type
 func isSimpleType(val reflect.Value, kind reflect.Kind, pointers **pointerInfo, interfaces *[]reflect.Value) bool {
 	switch kind {
 	case reflect.Bool:
@@ -158,6 +154,7 @@ func isSimpleType(val reflect.Value, kind reflect.Kind, pointers **pointerInfo,
 	return false
 }
 
+// dump value
 func printKeyValue(buf *bytes.Buffer, val reflect.Value, pointers **pointerInfo, interfaces *[]reflect.Value, structFilter func(string, string) bool, formatOutput bool, indent string, level int) {
 	var t = val.Kind()
 
@@ -367,6 +364,7 @@ func printKeyValue(buf *bytes.Buffer, val reflect.Value, pointers **pointerInfo,
 	}
 }
 
+// dump pointer value
 func printPointerInfo(buf *bytes.Buffer, headlen int, pointers *pointerInfo) {
 	var anyused = false
 	var pointerNum = 0
@@ -434,9 +432,7 @@ func printPointerInfo(buf *bytes.Buffer, headlen int, pointers *pointerInfo) {
 	}
 }
 
-//
-// get stack info
-//
+// get stack bytes
 func stack(skip int, indent string) []byte {
 	var buf = new(bytes.Buffer)
 
@@ -455,7 +451,7 @@ func stack(skip int, indent string) []byte {
 	return buf.Bytes()
 }
 
-// function returns, if possible, the name of the function containing the PC.
+// return the name of the function containing the PC if possible,
 func function(pc uintptr) []byte {
 	fn := runtime.FuncForPC(pc)
 	if fn == nil {
diff --git a/toolbox/healthcheck.go b/toolbox/healthcheck.go
index 224624ad..1540c7c7 100644
--- a/toolbox/healthcheck.go
+++ b/toolbox/healthcheck.go
@@ -13,12 +13,15 @@ package toolbox
 
 //AddHealthCheck("database",&DatabaseCheck{})
 
+// health checker map
 var AdminCheckList map[string]HealthChecker
 
+// health checker interface
 type HealthChecker interface {
 	Check() error
 }
 
+// add health checker with name string
 func AddHealthCheck(name string, hc HealthChecker) {
 	AdminCheckList[name] = hc
 }
diff --git a/toolbox/profile.go b/toolbox/profile.go
index 07d55d26..41721b09 100644
--- a/toolbox/profile.go
+++ b/toolbox/profile.go
@@ -19,6 +19,7 @@ func init() {
 	pid = os.Getpid()
 }
 
+// parse input command string
 func ProcessInput(input string, w io.Writer) {
 	switch input {
 	case "lookup goroutine":
@@ -44,6 +45,7 @@ func ProcessInput(input string, w io.Writer) {
 	}
 }
 
+// record memory profile in pprof
 func MemProf() {
 	if f, err := os.Create("mem-" + strconv.Itoa(pid) + ".memprof"); err != nil {
 		log.Fatal("record memory profile failed: %v", err)
@@ -54,6 +56,7 @@ func MemProf() {
 	}
 }
 
+// start cpu profile monitor
 func StartCPUProfile() {
 	f, err := os.Create("cpu-" + strconv.Itoa(pid) + ".pprof")
 	if err != nil {
@@ -62,10 +65,12 @@ func StartCPUProfile() {
 	pprof.StartCPUProfile(f)
 }
 
+// stop cpu profile monitor
 func StopCPUProfile() {
 	pprof.StopCPUProfile()
 }
 
+// print gc information to io.Writer
 func PrintGCSummary(w io.Writer) {
 	memStats := &runtime.MemStats{}
 	runtime.ReadMemStats(memStats)
@@ -114,7 +119,7 @@ func avg(items []time.Duration) time.Duration {
 	return time.Duration(int64(sum) / int64(len(items)))
 }
 
-// human readable format
+// format bytes number friendly
 func toH(bytes uint64) string {
 	switch {
 	case bytes < 1024:
diff --git a/toolbox/statistics.go b/toolbox/statistics.go
index b75cfb05..6042197e 100644
--- a/toolbox/statistics.go
+++ b/toolbox/statistics.go
@@ -7,6 +7,7 @@ import (
 	"time"
 )
 
+// Statistics struct
 type Statistics struct {
 	RequestUrl        string
 	RequestController string
@@ -16,12 +17,15 @@ type Statistics struct {
 	TotalTime         time.Duration
 }
 
+// UrlMap contains several statistics struct to log different data
 type UrlMap struct {
 	lock        sync.RWMutex
 	LengthLimit int //limit the urlmap's length if it's equal to 0 there's no limit
 	urlmap      map[string]map[string]*Statistics
 }
 
+// add statistics task.
+// it needs request method, request url, request controller and statistics time duration
 func (m *UrlMap) AddStatistics(requestMethod, requestUrl, requestController string, requesttime time.Duration) {
 	m.lock.Lock()
 	defer m.lock.Unlock()
@@ -65,6 +69,7 @@ func (m *UrlMap) AddStatistics(requestMethod, requestUrl, requestController stri
 	}
 }
 
+// put url statistics result in io.Writer
 func (m *UrlMap) GetMap(rw io.Writer) {
 	m.lock.RLock()
 	defer m.lock.RUnlock()
@@ -78,6 +83,7 @@ func (m *UrlMap) GetMap(rw io.Writer) {
 	}
 }
 
+// global statistics data map
 var StatisticsMap *UrlMap
 
 func init() {
diff --git a/toolbox/task.go b/toolbox/task.go
index ce9f56f9..b5558c15 100644
--- a/toolbox/task.go
+++ b/toolbox/task.go
@@ -53,6 +53,7 @@ const (
 	starBit = 1 << 63
 )
 
+// time taks schedule
 type Schedule struct {
 	Second uint64
 	Minute uint64
@@ -62,8 +63,10 @@ type Schedule struct {
 	Week   uint64
 }
 
+// task func type
 type TaskFunc func() error
 
+// task interface
 type Tasker interface {
 	GetStatus() string
 	Run() error
@@ -73,21 +76,24 @@ type Tasker interface {
 	GetPrev() time.Time
 }
 
+// task error
 type taskerr struct {
 	t       time.Time
 	errinfo string
 }
 
+// task struct
 type Task struct {
 	Taskname string
 	Spec     *Schedule
 	DoFunc   TaskFunc
 	Prev     time.Time
 	Next     time.Time
-	Errlist  []*taskerr //errtime:errinfo
-	ErrLimit int        //max length for the errlist 0 stand for there' no limit
+	Errlist  []*taskerr // like errtime:errinfo
+	ErrLimit int        // max length for the errlist, 0 stand for no limit
 }
 
+// add new task with name, time and func
 func NewTask(tname string, spec string, f TaskFunc) *Task {
 
 	task := &Task{
@@ -99,6 +105,7 @@ func NewTask(tname string, spec string, f TaskFunc) *Task {
 	return task
 }
 
+// get current task status
 func (tk *Task) GetStatus() string {
 	var str string
 	for _, v := range tk.Errlist {
@@ -107,6 +114,7 @@ func (tk *Task) GetStatus() string {
 	return str
 }
 
+// run task
 func (tk *Task) Run() error {
 	err := tk.DoFunc()
 	if err != nil {
@@ -117,53 +125,58 @@ func (tk *Task) Run() error {
 	return err
 }
 
+// set next time for this task
 func (tk *Task) SetNext(now time.Time) {
 	tk.Next = tk.Spec.Next(now)
 }
 
+// get the next call time of this task
 func (tk *Task) GetNext() time.Time {
 	return tk.Next
 }
+
+// set prev time of this task
 func (tk *Task) SetPrev(now time.Time) {
 	tk.Prev = now
 }
 
+// get prev time of this task
 func (tk *Task) GetPrev() time.Time {
 	return tk.Prev
 }
 
-//前6个字段分别表示：
-//       秒钟：0-59
-//       分钟：0-59
-//       小时：1-23
-//       日期：1-31
-//       月份：1-12
-//       星期：0-6（0表示周日）
+// six columns mean：
+//       second：0-59
+//       minute：0-59
+//       hour：1-23
+//       day：1-31
+//       month：1-12
+//       week：0-6（0 means Sunday）
 
-//还可以用一些特殊符号：
-//       *： 表示任何时刻
-//       ,：　表示分割，如第三段里：2,4，表示2点和4点执行
-//　　    －：表示一个段，如第三端里： 1-5，就表示1到5点
-//       /n : 表示每个n的单位执行一次，如第三段里，*/1, 就表示每隔1个小时执行一次命令。也可以写成1-23/1.
+// some signals：
+//       *： any time
+//       ,：　 separate signal
+//　　    －：duration
+//       /n : do as n times of time duration
 /////////////////////////////////////////////////////////
-//	0/30 * * * * *                        每30秒 执行
-//	0 43 21 * * *                         21:43 执行
-//	0 15 05 * * * 　　                     05:15 执行
-//	0 0 17 * * *                          17:00 执行
-//	0 0 17 * * 1                          每周一的 17:00 执行
-//	0 0,10 17 * * 0,2,3                   每周日,周二,周三的 17:00和 17:10 执行
-//	0 0-10 17 1 * *                       毎月1日从 17:00到7:10 毎隔1分钟 执行
-//	0 0 0 1,15 * 1                        毎月1日和 15日和 一日的 0:00 执行
-//	0 42 4 1 * * 　 　                     毎月1日的 4:42分 执行
-//	0 0 21 * * 1-6　　                     周一到周六 21:00 执行
-//	0 0,10,20,30,40,50 * * * *　           每隔10分 执行
-//	0 */10 * * * * 　　　　　　              每隔10分 执行
-//	0 * 1 * * *　　　　　　　　               从1:0到1:59 每隔1分钟 执行
-//	0 0 1 * * *　　　　　　　　               1:00 执行
-//	0 0 */1 * * *　　　　　　　               毎时0分 每隔1小时 执行
-//	0 0 * * * *　　　　　　　　               毎时0分 每隔1小时 执行
-//	0 2 8-20/3 * * *　　　　　　             8:02,11:02,14:02,17:02,20:02 执行
-//	0 30 5 1,15 * *　　　　　　              1日 和 15日的 5:30 执行
+//	0/30 * * * * *                        every 30s
+//	0 43 21 * * *                         21:43
+//	0 15 05 * * * 　　                     05:15
+//	0 0 17 * * *                          17:00
+//	0 0 17 * * 1                           17:00 in every Monday
+//	0 0,10 17 * * 0,2,3                   17:00 and 17:10 in every Sunday, Tuesday and Wednesday
+//	0 0-10 17 1 * *                       17:00 to 17:10 in 1 min duration each time on the first day of month
+//	0 0 0 1,15 * 1                        0:00 on the 1st day and 15th day of month
+//	0 42 4 1 * * 　 　                     4:42 on the 1st day of month
+//	0 0 21 * * 1-6　　                     21:00 from Monday to Saturday
+//	0 0,10,20,30,40,50 * * * *　           every 10 min duration
+//	0 */10 * * * * 　　　　　　              every 10 min duration
+//	0 * 1 * * *　　　　　　　　               1:00 to 1:59 in 1 min duration each time
+//	0 0 1 * * *　　　　　　　　               1:00
+//	0 0 */1 * * *　　　　　　　               0 min of hour in 1 hour duration
+//	0 0 * * * *　　　　　　　　               0 min of hour in 1 hour duration
+//	0 2 8-20/3 * * *　　　　　　             8:02, 11:02, 14:02, 17:02, 20:02
+//	0 30 5 1,15 * *　　　　　　              5:30 on the 1st day and 15th day of month
 func (t *Task) SetCron(spec string) {
 	t.Spec = t.parse(spec)
 }
@@ -252,6 +265,7 @@ func (t *Task) parseSpec(spec string) *Schedule {
 	return nil
 }
 
+// set schedule to next time
 func (s *Schedule) Next(t time.Time) time.Time {
 
 	// Start at the earliest possible time (the upcoming second).
@@ -349,6 +363,7 @@ func dayMatches(s *Schedule, t time.Time) bool {
 	return domMatch || dowMatch
 }
 
+// start all tasks
 func StartTask() {
 	go run()
 }
@@ -388,20 +403,23 @@ func run() {
 	}
 }
 
+// start all tasks
 func StopTask() {
 	stop <- true
 }
 
+// add task with name
 func AddTask(taskname string, t Tasker) {
 	AdminTaskList[taskname] = t
 }
 
-//sort map for tasker
+// sort map for tasker
 type MapSorter struct {
 	Keys []string
 	Vals []Tasker
 }
 
+// create new tasker map
 func NewMapSorter(m map[string]Tasker) *MapSorter {
 	ms := &MapSorter{
 		Keys: make([]string, 0, len(m)),
@@ -414,6 +432,7 @@ func NewMapSorter(m map[string]Tasker) *MapSorter {
 	return ms
 }
 
+// sort tasker map
 func (ms *MapSorter) Sort() {
 	sort.Sort(ms)
 }