diff --git a/session/sess_file.go b/session/sess_file.go
index c6dbf209..f7a739cc 100644
--- a/session/sess_file.go
+++ b/session/sess_file.go
@@ -15,11 +15,11 @@
 package session
 
 import (
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"os"
-	"errors"
 	"path"
 	"path/filepath"
 	"strings"
@@ -180,6 +180,10 @@ func (fp *FileProvider) SessionExist(sid string) bool {
 	filepder.lock.Lock()
 	defer filepder.lock.Unlock()
 
+	if len(sid) < 2 {
+		return false
+	}
+
 	_, err := os.Stat(path.Join(fp.savePath, string(sid[0]), string(sid[1]), sid))
 	return err == nil
 }
diff --git a/session/sess_file_test.go b/session/sess_file_test.go
new file mode 100644
index 00000000..0cf021db
--- /dev/null
+++ b/session/sess_file_test.go
@@ -0,0 +1,387 @@
+// Copyright 2014 beego Author. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package session
+
+import (
+	"fmt"
+	"os"
+	"sync"
+	"testing"
+	"time"
+)
+
+const sid = "Session_id"
+const sidNew = "Session_id_new"
+const sessionPath = "./_session_runtime"
+
+var (
+	mutex sync.Mutex
+)
+
+func TestFileProvider_SessionInit(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+	if fp.maxlifetime != 180 {
+		t.Error()
+	}
+
+	if fp.savePath != sessionPath {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionExist(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	if fp.SessionExist(sid) {
+		t.Error()
+	}
+
+	_, err := fp.SessionRead(sid)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if !fp.SessionExist(sid) {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionExist2(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	if fp.SessionExist(sid) {
+		t.Error()
+	}
+
+	if fp.SessionExist("") {
+		t.Error()
+	}
+
+	if fp.SessionExist("1") {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionRead(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	s, err := fp.SessionRead(sid)
+	if err != nil {
+		t.Error(err)
+	}
+
+	_ = s.Set("sessionValue", 18975)
+	v := s.Get("sessionValue")
+
+	if v.(int) != 18975 {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionRead1(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	_, err := fp.SessionRead("")
+	if err == nil {
+		t.Error(err)
+	}
+
+	_, err = fp.SessionRead("1")
+	if err == nil {
+		t.Error(err)
+	}
+}
+
+func TestFileProvider_SessionAll(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	sessionCount := 546
+
+	for i := 1; i <= sessionCount; i++ {
+		_, err := fp.SessionRead(fmt.Sprintf("%s_%d", sid, i))
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	if fp.SessionAll() != sessionCount {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionRegenerate(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	_, err := fp.SessionRead(sid)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if !fp.SessionExist(sid) {
+		t.Error()
+	}
+
+	_, err = fp.SessionRegenerate(sid, sidNew)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if fp.SessionExist(sid) {
+		t.Error()
+	}
+
+	if !fp.SessionExist(sidNew) {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionDestroy(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	_, err := fp.SessionRead(sid)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if !fp.SessionExist(sid) {
+		t.Error()
+	}
+
+	err = fp.SessionDestroy(sid)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if fp.SessionExist(sid) {
+		t.Error()
+	}
+}
+
+func TestFileProvider_SessionGC(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(1, sessionPath)
+
+	sessionCount := 412
+
+	for i := 1; i <= sessionCount; i++ {
+		_, err := fp.SessionRead(fmt.Sprintf("%s_%d", sid, i))
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	time.Sleep(2 * time.Second)
+
+	fp.SessionGC()
+	if fp.SessionAll() != 0 {
+		t.Error()
+	}
+}
+
+func TestFileSessionStore_Set(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	sessionCount := 100
+	s, _ := fp.SessionRead(sid)
+	for i := 1; i <= sessionCount; i++ {
+		err := s.Set(i, i)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+}
+
+func TestFileSessionStore_Get(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	sessionCount := 100
+	s, _ := fp.SessionRead(sid)
+	for i := 1; i <= sessionCount; i++ {
+		_ = s.Set(i, i)
+
+		v := s.Get(i)
+		if v.(int) != i {
+			t.Error()
+		}
+	}
+}
+
+func TestFileSessionStore_Delete(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	s, _ := fp.SessionRead(sid)
+	s.Set("1", 1)
+
+	if s.Get("1") == nil {
+		t.Error()
+	}
+
+	s.Delete("1")
+
+	if s.Get("1") != nil {
+		t.Error()
+	}
+}
+
+func TestFileSessionStore_Flush(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	sessionCount := 100
+	s, _ := fp.SessionRead(sid)
+	for i := 1; i <= sessionCount; i++ {
+		_ = s.Set(i, i)
+	}
+
+	_ = s.Flush()
+
+	for i := 1; i <= sessionCount; i++ {
+		if s.Get(i) != nil {
+			t.Error()
+		}
+	}
+}
+
+func TestFileSessionStore_SessionID(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+
+	sessionCount := 85
+
+	for i := 1; i <= sessionCount; i++ {
+		s, err := fp.SessionRead(fmt.Sprintf("%s_%d", sid, i))
+		if err != nil {
+			t.Error(err)
+		}
+		if s.SessionID() != fmt.Sprintf("%s_%d", sid, i) {
+			t.Error(err)
+		}
+	}
+}
+
+func TestFileSessionStore_SessionRelease(t *testing.T) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	os.RemoveAll(sessionPath)
+	defer os.RemoveAll(sessionPath)
+	fp := &FileProvider{}
+
+	_ = fp.SessionInit(180, sessionPath)
+	filepder.savePath = sessionPath
+	sessionCount := 85
+
+	for i := 1; i <= sessionCount; i++ {
+		s, err := fp.SessionRead(fmt.Sprintf("%s_%d", sid, i))
+		if err != nil {
+			t.Error(err)
+		}
+
+
+		s.Set(i,i)
+		s.SessionRelease(nil)
+	}
+
+	for i := 1; i <= sessionCount; i++ {
+		s, err := fp.SessionRead(fmt.Sprintf("%s_%d", sid, i))
+		if err != nil {
+			t.Error(err)
+		}
+
+		if s.Get(i).(int) != i {
+			t.Error()
+		}
+	}
+}
\ No newline at end of file