diff --git a/auth/auth_test.go b/auth/auth_test.go
index a5890bd69..e49815230 100644
--- a/auth/auth_test.go
+++ b/auth/auth_test.go
@@ -1,9 +1,40 @@
+/*
+   Copyright (c) 2016 VMware, Inc. 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 auth
 
 import (
 	"testing"
+	"time"
 )
 
-func TestMain(t *testing.T) {
-}
+var l = NewUserLock(2 * time.Second)
 
+func TestLock(t *testing.T) {
+	t.Log("Locking john")
+	l.Lock("john")
+	if !l.IsLocked("john") {
+		t.Errorf("John should be locked")
+	}
+	t.Log("Locking jack")
+	l.Lock("jack")
+	t.Log("Sleep for 2 seconds and check...")
+	time.Sleep(2 * time.Second)
+	if l.IsLocked("jack") {
+		t.Errorf("After 2 seconds, jack shouldn't be locked")
+	}
+	if l.IsLocked("daniel") {
+		t.Errorf("daniel has never been locked, he should not be locked")
+	}
+}
diff --git a/auth/authenticator.go b/auth/authenticator.go
index 1640a842e..66f6bae36 100644
--- a/auth/authenticator.go
+++ b/auth/authenticator.go
@@ -17,13 +17,18 @@ package auth
 
 import (
 	"fmt"
-	"os"
-
 	"github.com/vmware/harbor/utils/log"
+	"os"
+	"time"
 
 	"github.com/vmware/harbor/models"
 )
 
+// 1.5 seconds
+const frozenTime time.Duration = 1500 * time.Millisecond
+
+var lock = NewUserLock(frozenTime)
+
 // Authenticator provides interface to authenticate user credentials.
 type Authenticator interface {
 
@@ -55,5 +60,15 @@ func Login(m models.AuthModel) (*models.User, error) {
 	if !ok {
 		return nil, fmt.Errorf("Unrecognized auth_mode: %s", authMode)
 	}
-	return authenticator.Authenticate(m)
+	if lock.IsLocked(m.Principal) {
+		log.Debugf("%s is locked due to login failure, login failed", m.Principal)
+		return nil, nil
+	}
+	user, err := authenticator.Authenticate(m)
+	if user == nil && err == nil {
+		log.Debugf("Login failed, locking %s, and sleep for %v", m.Principal, frozenTime)
+		lock.Lock(m.Principal)
+		time.Sleep(frozenTime)
+	}
+	return user, err
 }
diff --git a/auth/lock.go b/auth/lock.go
new file mode 100644
index 000000000..2d8930987
--- /dev/null
+++ b/auth/lock.go
@@ -0,0 +1,52 @@
+/*
+   Copyright (c) 2016 VMware, Inc. 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 auth
+
+import (
+	"sync"
+	"time"
+)
+
+// UserLock maintains a lock to block user from logging in within a short period of time.
+type UserLock struct {
+	failures map[string]time.Time
+	d        time.Duration
+	rw       *sync.RWMutex
+}
+
+// NewUserLock ...
+func NewUserLock(freeze time.Duration) *UserLock {
+	return &UserLock{
+		make(map[string]time.Time),
+		freeze,
+		&sync.RWMutex{},
+	}
+}
+
+// Lock marks a new login failure with the time it happens
+func (ul *UserLock) Lock(username string) {
+	ul.rw.Lock()
+	defer ul.rw.Unlock()
+	ul.failures[username] = time.Now()
+}
+
+// IsLocked checks whether a login request is happened within a period of time or not
+// if it is, the authenticator should ignore the login request and return a failure immediately
+func (ul *UserLock) IsLocked(username string) bool {
+	ul.rw.RLock()
+	defer ul.rw.RUnlock()
+	return time.Now().Sub(ul.failures[username]) <= ul.d
+}