diff --git a/conf/nginx_docklet.conf b/conf/nginx_docklet.conf
index 1ab42ad..d97042a 100644
--- a/conf/nginx_docklet.conf
+++ b/conf/nginx_docklet.conf
@@ -1,6 +1,9 @@
 server
 {
-         listen     %NGINX_PORT;
+         listen %NGINX_PORT;
+         #ssl on;
+         #ssl_certificate /etc/nginx/ssl/1604242_iwork.pku.edu.cn.pem;
+         #ssl_certificate_key /etc/nginx/ssl/1604242_iwork.pku.edu.cn.key;
          server_name    nginx_docklet.conf;
          charset UTF-8;
          add_header X-Frame-Options SAMEORIGIN;
diff --git a/src/master/userManager.py b/src/master/userManager.py
index 782217f..4f7d5f1 100755
--- a/src/master/userManager.py
+++ b/src/master/userManager.py
@@ -7,7 +7,7 @@ Warning: in some early versions, "token" stand for the instance of class model.U
 Original author: Liu Peidong
 '''
 
-from utils.model import db, User, UserGroup, Notification, UserUsage, LoginMsg
+from utils.model import db, User, UserGroup, Notification, UserUsage, LoginMsg, LoginFailMsg
 from functools import wraps
 import os, subprocess, math
 import hashlib
@@ -19,7 +19,7 @@ import smtplib
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
 from email.header import Header
-from datetime import datetime
+from datetime import datetime, timedelta
 import json
 from utils.log import logger
 from utils.lvmtool import *
@@ -144,7 +144,6 @@ class userManager:
         '''
         try:
             User.query.all()
-            LoginMsg.query.all()
         except:
             db.create_all()
             if password == None:
@@ -202,6 +201,8 @@ class userManager:
 
         try:
             UserUsage.query.all()
+            LoginMsg.query.all()
+            LoginFailMsg.query.all()
         except:
             db.create_all()
 
@@ -327,7 +328,22 @@ class userManager:
         return a token as well as some user information
         '''
         user = User.query.filter_by(username = username).first()
+        failmsg = LoginFailMsg.query.filter_by(username = username).first()
         result = {}
+        if failmsg == None:
+            newfailmsg = LoginFailMsg(username)
+            db.session.add(newfailmsg)
+            db.session.commit()
+            failmsg = newfailmsg
+        elif failmsg.failcnt > 40:
+            reason = "You have been input wrong password over 40 times. You account will be locked. Please contact administrators for help."
+            logger.info("Login failed: userip=%s reason:%s" % (userip,reason))
+            return {'success':'false', 'reason':reason}
+        elif datetime.now() < failmsg.bantime:
+            reason = "You have been input wrong password %d times. Please try after %s." % (failmsg.failcnt, failmsg.bantime.strftime("%Y-%m-%d %H:%M:%S"))
+            logger.info("Login failed: userip=%s reason:%s" % (userip,reason))
+            return {'success':'false', 'reason':reason}
+
         if (user == None or user.auth_method =='local'):
             result = self.auth_local(username, password)
         elif (user.auth_method == 'pam'):
@@ -337,11 +353,20 @@ class userManager:
 
         if result['success'] == 'true':
             loginmsg = LoginMsg(result['data']['username'],userip)
+            failmsg.failcnt = 0
             db.session.add(loginmsg)
             db.session.commit()
             logger.info("Login success: username=%s, userip=%s" % (result['data']['username'], userip))
         else:
             logger.info("Login failed: userip=%s" % (userip))
+            failmsg.failcnt += 1
+            if failmsg.failcnt == 10:
+                failmsg.bantime = datetime.now() + timedelta(minutes=10)
+            elif failmsg.failcnt == 20:
+                failmsg.bantime = datetime.now() + timedelta(minutes=100)
+            elif failmsg.failcnt == 30:
+                failmsg.bantime = datetime.now() + timedelta(days=1)
+            db.session.commit()
         return result
 
     def auth_token(self, token):
diff --git a/src/utils/model.py b/src/utils/model.py
index f8e9651..37ef56c 100755
--- a/src/utils/model.py
+++ b/src/utils/model.py
@@ -221,6 +221,20 @@ class LoginMsg(db.Model):
     def __repr__(self):
         return '<id=%d, username=%s, userip=%s, time=%s>' % (self.id,self.username,self.userip,self.time.strftime("%Y-%m-%d %H:%M:%S"))
 
+class LoginFailMsg(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    username = db.Column(db.String(10), unique=True)
+    failcnt = db.Column(db.Integer)
+    bantime = db.Column(db.DateTime)
+
+    def __init__(self, username):
+        self.username = username
+        self.failcnt = 0
+        self.bantime = datetime.now()
+
+    def __repr__(self):
+        return '<id=%d, username=%s, failcnt=%d, bantime=%s>' % (self.id,self.username,self.failcnt,self.bantime.strftime("%Y-%m-%d %H:%M:%S"))
+
 class VNode(db.Model):
     __bind_key__ = 'history'
     name = db.Column(db.String(100), primary_key=True)