diff --git a/cache/README.md b/cache/README.md
index 4152c57e..957790e7 100644
--- a/cache/README.md
+++ b/cache/README.md
@@ -26,7 +26,7 @@ Then init a Cache (example with memory adapter)
 
 Use it like this:	
 	
-	bm.Put("astaxie", 1, 10)
+	bm.Put("astaxie", 1, 10 * time.Second)
 	bm.Get("astaxie")
 	bm.IsExist("astaxie")
 	bm.Delete("astaxie")
diff --git a/cache/cache.go b/cache/cache.go
index c9904444..2008402e 100644
--- a/cache/cache.go
+++ b/cache/cache.go
@@ -23,7 +23,7 @@
 //
 // Use it like this:
 //
-//	bm.Put("astaxie", 1, 10)
+//	bm.Put("astaxie", 1, 10 * time.Second)
 //	bm.Get("astaxie")
 //	bm.IsExist("astaxie")
 //	bm.Delete("astaxie")
@@ -33,13 +33,14 @@ package cache
 
 import (
 	"fmt"
+	"time"
 )
 
 // Cache interface contains all behaviors for cache adapter.
 // usage:
 //	cache.Register("file",cache.NewFileCache) // this operation is run in init method of file.go.
 //	c,err := cache.NewCache("file","{....}")
-//	c.Put("key",value,3600)
+//	c.Put("key",value, 3600 * time.Second)
 //	v := c.Get("key")
 //
 //	c.Incr("counter")  // now is 1
@@ -51,7 +52,7 @@ type Cache interface {
 	// GetMulti is a batch version of Get.
 	GetMulti(keys []string) []interface{}
 	// set cached value with key and expire time.
-	Put(key string, val interface{}, timeout int64) error
+	Put(key string, val interface{}, timeout time.Duration) error
 	// delete cached value by key.
 	Delete(key string) error
 	// increase cached int value by key, as a counter.
diff --git a/cache/cache_test.go b/cache/cache_test.go
index 481309fd..9ceb606a 100644
--- a/cache/cache_test.go
+++ b/cache/cache_test.go
@@ -25,7 +25,8 @@ func TestCache(t *testing.T) {
 	if err != nil {
 		t.Error("init err")
 	}
-	if err = bm.Put("astaxie", 1, 10); err != nil {
+	timeoutDuration := 10 * time.Second
+	if err = bm.Put("astaxie", 1, timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -42,7 +43,7 @@ func TestCache(t *testing.T) {
 		t.Error("check err")
 	}
 
-	if err = bm.Put("astaxie", 1, 10); err != nil {
+	if err = bm.Put("astaxie", 1, timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 
@@ -67,7 +68,7 @@ func TestCache(t *testing.T) {
 	}
 
 	//test GetMulti
-	if err = bm.Put("astaxie", "author", 10); err != nil {
+	if err = bm.Put("astaxie", "author", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -77,7 +78,7 @@ func TestCache(t *testing.T) {
 		t.Error("get err")
 	}
 
-	if err = bm.Put("astaxie1", "author1", 10); err != nil {
+	if err = bm.Put("astaxie1", "author1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie1") {
@@ -101,7 +102,8 @@ func TestFileCache(t *testing.T) {
 	if err != nil {
 		t.Error("init err")
 	}
-	if err = bm.Put("astaxie", 1, 10); err != nil {
+	timeoutDuration := 10 * time.Second
+	if err = bm.Put("astaxie", 1, timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -133,7 +135,7 @@ func TestFileCache(t *testing.T) {
 	}
 
 	//test string
-	if err = bm.Put("astaxie", "author", 10); err != nil {
+	if err = bm.Put("astaxie", "author", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -144,7 +146,7 @@ func TestFileCache(t *testing.T) {
 	}
 
 	//test GetMulti
-	if err = bm.Put("astaxie1", "author1", 10); err != nil {
+	if err = bm.Put("astaxie1", "author1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie1") {
diff --git a/cache/file.go b/cache/file.go
index 2d77b567..3a7aa8b0 100644
--- a/cache/file.go
+++ b/cache/file.go
@@ -33,8 +33,8 @@ import (
 // it contains data and expire time.
 type FileCacheItem struct {
 	Data       interface{}
-	Lastaccess int64
-	Expired    int64
+	Lastaccess time.Time
+	Expired    time.Time
 }
 
 // FileCache Config
@@ -42,7 +42,7 @@ var (
 	FileCachePath           = "cache" // cache directory
 	FileCacheFileSuffix     = ".bin"  // cache file suffix
 	FileCacheDirectoryLevel = 2       // cache file deep level if auto generated cache files.
-	FileCacheEmbedExpiry    int64     // cache expire time, default is no expire forever.
+	FileCacheEmbedExpiry    time.Duration = 0     // cache expire time, default is no expire forever.
 )
 
 // FileCache is cache adapter for file storage.
@@ -76,7 +76,7 @@ func (fc *FileCache) StartAndGC(config string) error {
 		cfg["DirectoryLevel"] = strconv.Itoa(FileCacheDirectoryLevel)
 	}
 	if _, ok := cfg["EmbedExpiry"]; !ok {
-		cfg["EmbedExpiry"] = strconv.FormatInt(FileCacheEmbedExpiry, 10)
+		cfg["EmbedExpiry"] = strconv.FormatInt(int64(FileCacheEmbedExpiry.Seconds()), 10)
 	}
 	fc.CachePath = cfg["CachePath"]
 	fc.FileSuffix = cfg["FileSuffix"]
@@ -123,7 +123,7 @@ func (fc *FileCache) Get(key string) interface{} {
 	}
 	var to FileCacheItem
 	GobDecode(fileData, &to)
-	if to.Expired < time.Now().Unix() {
+	if to.Expired.Before(time.Now()) {
 		return ""
 	}
 	return to.Data
@@ -142,16 +142,16 @@ func (fc *FileCache) GetMulti(keys []string) []interface{} {
 // Put value into file cache.
 // timeout means how long to keep this file, unit of ms.
 // if timeout equals FileCacheEmbedExpiry(default is 0), cache this item forever.
-func (fc *FileCache) Put(key string, val interface{}, timeout int64) error {
+func (fc *FileCache) Put(key string, val interface{}, timeout time.Duration) error {
 	gob.Register(val)
 
 	item := FileCacheItem{Data: val}
 	if timeout == FileCacheEmbedExpiry {
-		item.Expired = time.Now().Unix() + (86400 * 365 * 10) // ten years
+		item.Expired = time.Now().Add((86400 * 365 * 10) * time.Second) // ten years
 	} else {
-		item.Expired = time.Now().Unix() + timeout
+		item.Expired = time.Now().Add(timeout)
 	}
-	item.Lastaccess = time.Now().Unix()
+	item.Lastaccess = time.Now()
 	data, err := GobEncode(item)
 	if err != nil {
 		return err
diff --git a/cache/memcache/memcache.go b/cache/memcache/memcache.go
index 272124da..15ea5d3e 100644
--- a/cache/memcache/memcache.go
+++ b/cache/memcache/memcache.go
@@ -37,6 +37,7 @@ import (
 	"github.com/bradfitz/gomemcache/memcache"
 
 	"github.com/astaxie/beego/cache"
+	"time"
 )
 
 // Cache Memcache adapter.
@@ -89,7 +90,7 @@ func (rc *Cache) GetMulti(keys []string) []interface{} {
 }
 
 // Put put value to memcache. only support string.
-func (rc *Cache) Put(key string, val interface{}, timeout int64) error {
+func (rc *Cache) Put(key string, val interface{}, timeout time.Duration) error {
 	if rc.conn == nil {
 		if err := rc.connectInit(); err != nil {
 			return err
@@ -99,7 +100,7 @@ func (rc *Cache) Put(key string, val interface{}, timeout int64) error {
 	if !ok {
 		return errors.New("val must string")
 	}
-	item := memcache.Item{Key: key, Value: []byte(v), Expiration: int32(timeout)}
+	item := memcache.Item{Key: key, Value: []byte(v), Expiration: int32(timeout/time.Second)}
 	return rc.conn.Set(&item)
 }
 
diff --git a/cache/memcache/memcache_test.go b/cache/memcache/memcache_test.go
index 27b085e6..19629059 100644
--- a/cache/memcache/memcache_test.go
+++ b/cache/memcache/memcache_test.go
@@ -28,7 +28,8 @@ func TestMemcacheCache(t *testing.T) {
 	if err != nil {
 		t.Error("init err")
 	}
-	if err = bm.Put("astaxie", "1", 10); err != nil {
+	timeoutDuration := 10 * time.Second
+	if err = bm.Put("astaxie", "1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -40,7 +41,7 @@ func TestMemcacheCache(t *testing.T) {
 	if bm.IsExist("astaxie") {
 		t.Error("check err")
 	}
-	if err = bm.Put("astaxie", "1", 10); err != nil {
+	if err = bm.Put("astaxie", "1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 
@@ -69,7 +70,7 @@ func TestMemcacheCache(t *testing.T) {
 	}
 
 	//test string
-	if err = bm.Put("astaxie", "author", 10); err != nil {
+	if err = bm.Put("astaxie", "author", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -81,7 +82,7 @@ func TestMemcacheCache(t *testing.T) {
 	}
 
 	//test GetMulti
-	if err = bm.Put("astaxie1", "author1", 10); err != nil {
+	if err = bm.Put("astaxie1", "author1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie1") {
diff --git a/cache/memory.go b/cache/memory.go
index f8cccb14..d928afdb 100644
--- a/cache/memory.go
+++ b/cache/memory.go
@@ -17,7 +17,6 @@ package cache
 import (
 	"encoding/json"
 	"errors"
-	"fmt"
 	"sync"
 	"time"
 )
@@ -31,7 +30,7 @@ var (
 type MemoryItem struct {
 	val         interface{}
 	createdTime time.Time
-	lifespan    int64
+	lifespan    time.Duration
 }
 
 func (mi *MemoryItem) isExpire() bool {
@@ -39,7 +38,7 @@ func (mi *MemoryItem) isExpire() bool {
 	if mi.lifespan == 0 {
 		return false
 	}
-	return time.Now().Unix()-mi.createdTime.Unix() > mi.lifespan
+	return time.Now().Sub(mi.createdTime) > mi.lifespan
 }
 
 // MemoryCache is Memory cache adapter.
@@ -83,7 +82,7 @@ func (bc *MemoryCache) GetMulti(names []string) []interface{} {
 
 // Put cache to memory.
 // if lifespan is 0, it will be forever till restart.
-func (bc *MemoryCache) Put(name string, value interface{}, lifespan int64) error {
+func (bc *MemoryCache) Put(name string, value interface{}, lifespan time.Duration) error {
 	bc.Lock()
 	defer bc.Unlock()
 	bc.items[name] = &MemoryItem{
@@ -201,10 +200,7 @@ func (bc *MemoryCache) StartAndGC(config string) error {
 		cf = make(map[string]int)
 		cf["interval"] = DefaultEvery
 	}
-	dur, err := time.ParseDuration(fmt.Sprintf("%ds", cf["interval"]))
-	if err != nil {
-		return err
-	}
+	dur :=  time.Duration(cf["interval"]) * time.Second
 	bc.Every = cf["interval"]
 	bc.dur = dur
 	go bc.vaccuum()
diff --git a/cache/redis/redis.go b/cache/redis/redis.go
index 60c1702a..781e3836 100644
--- a/cache/redis/redis.go
+++ b/cache/redis/redis.go
@@ -109,9 +109,9 @@ ERROR:
 }
 
 // Put put cache to redis.
-func (rc *Cache) Put(key string, val interface{}, timeout int64) error {
+func (rc *Cache) Put(key string, val interface{}, timeout time.Duration) error {
 	var err error
-	if _, err = rc.do("SETEX", key, timeout, val); err != nil {
+	if _, err = rc.do("SETEX", key, int64(timeout/time.Second), val); err != nil {
 		return err
 	}
 
diff --git a/cache/redis/redis_test.go b/cache/redis/redis_test.go
index 142b6d3c..47c5acc6 100644
--- a/cache/redis/redis_test.go
+++ b/cache/redis/redis_test.go
@@ -28,7 +28,8 @@ func TestRedisCache(t *testing.T) {
 	if err != nil {
 		t.Error("init err")
 	}
-	if err = bm.Put("astaxie", 1, 10); err != nil {
+	timeoutDuration := 10 * time.Second
+	if err = bm.Put("astaxie", 1, timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -40,7 +41,7 @@ func TestRedisCache(t *testing.T) {
 	if bm.IsExist("astaxie") {
 		t.Error("check err")
 	}
-	if err = bm.Put("astaxie", 1, 10); err != nil {
+	if err = bm.Put("astaxie", 1, timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 
@@ -69,7 +70,7 @@ func TestRedisCache(t *testing.T) {
 	}
 
 	//test string
-	if err = bm.Put("astaxie", "author", 10); err != nil {
+	if err = bm.Put("astaxie", "author", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie") {
@@ -81,7 +82,7 @@ func TestRedisCache(t *testing.T) {
 	}
 
 	//test GetMulti
-	if err = bm.Put("astaxie1", "author1", 10); err != nil {
+	if err = bm.Put("astaxie1", "author1", timeoutDuration); err != nil {
 		t.Error("set Error", err)
 	}
 	if !bm.IsExist("astaxie1") {
diff --git a/utils/captcha/captcha.go b/utils/captcha/captcha.go
index 76301a03..4ac5c9f9 100644
--- a/utils/captcha/captcha.go
+++ b/utils/captcha/captcha.go
@@ -64,6 +64,7 @@ import (
 	"net/http"
 	"path"
 	"strings"
+	"time"
 
 	"github.com/astaxie/beego"
 	"github.com/astaxie/beego/cache"
@@ -78,7 +79,7 @@ var (
 const (
 	// default captcha attributes
 	challengeNums    = 6
-	expiration       = 600
+	expiration       = 600 * time.Second
 	fieldIDName      = "captcha_id"
 	fieldCaptchaName = "captcha"
 	cachePrefix      = "captcha_"
@@ -106,7 +107,7 @@ type Captcha struct {
 	ChallengeNums int
 
 	// captcha expiration seconds
-	Expiration int64
+	Expiration time.Duration
 
 	// cache key prefix
 	CachePrefix string