diff --git a/module/extension/control.php b/module/extension/control.php
index 492b4a2025..179fb9afa9 100644
--- a/module/extension/control.php
+++ b/module/extension/control.php
@@ -74,7 +74,7 @@ class extension extends control
      * @access public
      * @return void
      */
-    public function install($extension, $downLink = '', $md5 = '', $forceInstall = 'no')
+    public function install($extension, $downLink = '', $md5 = '', $forceInstall = 'no', $isCheck = true)
     {
         $this->view->error = '';
         $this->view->header->title = $this->lang->extension->install . $this->lang->colon . $extension;
@@ -134,12 +134,20 @@ class extension extends control
 
         /* Extract the package. */
         $return = $this->extension->extractPackage($extension);
-        if($return->result != 'ok')
+       if($return->result != 'ok')
         {
             $this->view->error = sprintf($this->lang->extension->errorExtracted, $packageFile, $return->error);
             die($this->display());
         }
 
+       $return = $this->extension->checkFile($extension, 'repeat', $isCheck);
+        if($return->result != 'ok')
+        {
+            $continueLink = inlink('install', "extension=$extension&downLink=&md5=&forecInstall=&isCheck=" . false);
+            $resetLink    = inlink('obtain');
+            $this->view->error = sprintf($this->lang->extension->errorRepeatFile, $return->error, $continueLink, $resetLink);
+            die($this->display());
+        }
         /* Save to database. */
         $this->extension->saveExtension($extension);
 
@@ -179,11 +187,24 @@ class extension extends control
      * @access public
      * @return void
      */
-    public function uninstall($extension)
+    public function uninstall($extension,$isCheck = true)
     {
+        $return->return         = 'ok';
+        $checkReturn = $this->extension->checkFile($extension, 'change', $isCheck);
+        if($checkReturn->result != 'ok')
+        {
+            $continueLink = inlink('uninstall', "extension=$extension&isCheck=" . false);
+            $resetLink    = inlink('browse');
+            $return->removeCommands = sprintf($this->lang->extension->errorChangeFile, $checkReturn->error, $continueLink, $resetLink);
+            $return->return         = 'fail';
+            $this->view->return     = $return;
+            die($this->display());
+        }
+
         $this->extension->executeDB($extension, 'uninstall');
         $this->extension->updateExtension($extension, array('status' => 'available'));
-        $this->view->removeCommands = $this->extension->removePackage($extension);
+        $return->removeCommands     = $this->extension->removePackage($extension);
+        $this->view->return         = $return;
         $this->view->header->title  = $this->lang->extension->uninstallFinished;
         $this->display();
     }
@@ -195,8 +216,18 @@ class extension extends control
      * @access public
      * @return void
      */
-    public function activate($extension)
+    public function activate($extension, $isCheck = true)
     {
+        $return = $this->extension->checkFile($extension, 'repeat', $isCheck);
+        if($return->result != 'ok')
+        {
+            $continueLink = inlink('activate', "extension=$extension&isCheck=" . false);
+            $resetLink    = inlink('browse', 'type=deactivated');
+            $return->error = sprintf($this->lang->extension->errorRepeatFile, $return->error, $continueLink, $resetLink);
+            $this->view->return     = $return;
+            die($this->display());
+        }
+
         $this->extension->copyPackageFiles($extension);
         $this->extension->updateExtension($extension, array('status' => 'installed'));
         $this->view->header->title = $this->lang->extension->activateFinished;
@@ -210,10 +241,22 @@ class extension extends control
      * @access public
      * @return void
      */
-    public function deactivate($extension)
+    public function deactivate($extension, $isCheck = true)
     {
+        $return->return         = 'ok';
+        $checkReturn = $this->extension->checkFile($extension, 'change', $isCheck);
+        if($checkReturn->result != 'ok')
+        {
+            $continueLink = inlink('deactivate', "extension=$extension&isCheck=" . false);
+            $resetLink    = inlink('browse');
+            $return->removeCommands = sprintf($this->lang->extension->errorChangeFile, $checkReturn->error, $continueLink, $resetLink);
+            $return->return         = 'fail';
+            $this->view->return     = $return;
+            die($this->display());
+        }
         $this->extension->updateExtension($extension, array('status' => 'deactivated'));
-        $this->view->removeCommands = $this->extension->removePackage($extension);
+        $return->removeCommands = $this->extension->removePackage($extension);
+        $this->view->return   = $return;
         $this->view->header->title  = $this->lang->extension->deactivateFinished;
         $this->display();
     }
diff --git a/module/extension/lang/zh-cn.php b/module/extension/lang/zh-cn.php
index 839098896c..6f1857b733 100644
--- a/module/extension/lang/zh-cn.php
+++ b/module/extension/lang/zh-cn.php
@@ -65,7 +65,9 @@ $lang->extension->errorDownloadPathNotWritable = '插件下载存储路径<stron
 $lang->extension->errorPackageFileExists       = '下载路径已经有一个名为的<strong>%s</strong>附件。<h3>重新安装，<a href="%s">请点击此链接</a></h3>';
 $lang->extension->errorDownloadFailed          = '下载失败，请重新下载。如果多次重试还不行，请尝试手工下载，然后通过上传功能上传。';
 $lang->extension->errorMd5Checking             = '下载文件不完整，请重新下载。如果多次重试还不行，请尝试手工下载，然后通过上传功能上传。';
-$lang->extension->errorExtracted               = '包文件<strong> %s </strong>解压缩失败，可能不是一个有效的zip文件。错误信息如下：<br />';
+$lang->extension->errorExtracted               = '包文件<strong> %s </strong>解压缩失败，可能不是一个有效的zip文件。错误信息如下：<br />%s';
+$lang->extension->errorRepeatFile              = '有以下安装文件重复：<br />%s。<h3>是否继续安装，<a href="%s">覆盖安装</a>&nbsp;&nbsp;<a href="#" onclick=parent.location.href="%s">取消</a></h3>';
+$lang->extension->errorChangeFile              = '有以下安装文件做过改动：<br />%s。<h3>是否继续，<a href="%s">确定删除</a>&nbsp;&nbsp;<a href="#" onclick=parent.location.href="%s">取消</a></h3>';
 $lang->extension->errorPackageNotFound         = '包文件 <strong>%s </strong>没有找到，可能是因为自动下载失败。您可以尝试再次下载。';
 $lang->extension->errorTargetPathNotWritable   = '目标路径 <strong>%s </strong>不可写。';
 $lang->extension->errorTargetPathNotExists     = '目标路径 <strong>%s </strong>不存在。';
diff --git a/module/extension/model.php b/module/extension/model.php
index b1cb99a02d..64bb7900a8 100644
--- a/module/extension/model.php
+++ b/module/extension/model.php
@@ -352,7 +352,6 @@ class extensionModel extends model
             if($path == 'db' or $path == 'doc' or $path == '..' or $path == '.') continue;
             $copiedFiles = $this->copyDir($extensionDir . $path, $appRoot . $path);
         }
-
         return $copiedFiles;
     }
 
@@ -513,7 +512,7 @@ class extensionModel extends model
         $data = (object)$data;
         $appRoot = $this->app->getAppRoot();
 
-        if(isset($data->dirs) and $data->dirs)
+        if(isset($data->dirs))
         {
             foreach($data->dirs as $key => $dir)
             {
@@ -612,4 +611,81 @@ class extensionModel extends model
         if(!@rmdir($dir)) return false;
         return true;
     }
+    
+    /**
+     * Check the file for repeat or changed
+     * 
+     * @param  string    $moveFile 
+     * @param  string    $extensionFile 
+     * @access public
+     * @return object
+     */
+    public function checkFile($extension,$type = 'repeat', $isCheck = true)
+    {
+        $return->result = 'ok';
+        $return->error  = '';
+        if(!$isCheck) return $return;
+
+        $extensionFiles = $this->getAllExtensionFile($extension);
+        $appRoot = $this->app->getAppRoot();
+        foreach($extensionFiles as $extensionFile)
+        {
+            $compareFile = $appRoot . str_replace(realpath("ext/$extension") . '/', '', $extensionFile);
+            if(!file_exists($compareFile)) continue;
+            if($type =='repeat' and md5_file($extensionFile) == md5_file($compareFile)) $return->error .= $compareFile . '<br />';
+            elseif($type =='change' and md5_file($extensionFile) != md5_file($compareFile)) $return->error .= $compareFile . '<br />';
+        }
+        if($return->error != '') $return->result = 'fail';
+        return $return;
+    }
+
+    /**
+     * Get all extension files 
+     * 
+     * @param  string    $extension 
+     * @access public
+     * @return array
+     */
+    public function getAllExtensionFile($extension)
+    {
+        $extensionDir = "ext/$extension/";
+        $files = $this->getFile($extensionDir, array('db', 'doc'));
+        return $files;
+
+    }
+
+    /**
+     * Foreach the dir's files
+     * 
+     * @param  string    $dir 
+     * @param  array     $exceptions 
+     * @access private
+     * @return array
+     */
+    private function getFile($dir, $exceptions = array())
+    {
+         static $files = array();
+
+         if(!is_dir($dir)) return $files;
+
+         $dir    = realpath($dir) . '/';
+         $entries = scandir($dir);
+ 
+         foreach($entries as $entry)
+         {
+             if($entry == '.' or $entry == '..') continue;
+             if(in_array($entry, $exceptions)) continue;
+             $fullEntry = $dir . $entry;
+             if(is_file($fullEntry))
+             {
+                 $files[] = $dir . $entry;
+             }
+             else
+             {
+                 $nextDir = $dir . $entry;
+                 $this->getFile($nextDir);
+             }
+         }
+         return $files;
+    }
 }
diff --git a/module/extension/view/activate.html.php b/module/extension/view/activate.html.php
index a3c58cd27c..c86f4a0655 100644
--- a/module/extension/view/activate.html.php
+++ b/module/extension/view/activate.html.php
@@ -15,10 +15,17 @@
   <caption><?php echo $header->title;?></caption>
   <tr>
     <td valign='middle'>
-      <?php
-      echo "<h3 class='a-center success'>{$header->title}</h3>";
-      echo "<p class='a-center'>" . html::commonButton($lang->extension->viewInstalled, 'onclick=parent.location.href="' . inlink('browse', 'type=installed') . '"') . '</p>';
-      ?>
+     <?php
+    if(isset($return) and $return->return == 'fail')
+    {
+        echo $return->error;
+    }
+    else
+    {
+        echo "<h3 class='a-center success'>{$header->title}</h3>";
+        echo "<p class='a-center'>" . html::commonButton($lang->extension->viewInstalled, 'onclick=parent.location.href="' . inlink('browse', 'type=installed') . '"') . '</p>';
+    }
+    ?>
     </td>
   </tr>
 </table>
diff --git a/module/extension/view/deactivate.html.php b/module/extension/view/deactivate.html.php
index b89d206c58..32734f44d4 100644
--- a/module/extension/view/deactivate.html.php
+++ b/module/extension/view/deactivate.html.php
@@ -15,15 +15,22 @@
   <caption><?php echo $header->title;?></caption>
   <tr>
     <td valign='middle'>
-      <?php
+<?php
+if($return->return == 'fail')
+{
+    echo $return->removeCommands;
+}
+else
+{
       echo "<h3 class='a-center success'>{$header->title}</h3>";
-      if($removeCommands)
+      if($return->removeCommands)
       {
           echo "<p class='strong'>{$lang->extension->unremovedFiles}</p>";
-          echo join($removeCommands, '<br />');
+          echo join($retrun->removeCommands, '<br />');
       }
       echo "<p class='a-center'>" . html::commonButton($lang->extension->viewDeactivated, 'onclick=parent.location.href="' . inlink('browse', 'type=deactivated') . '"') . '</p>';
-      ?>
+}
+?>
     </td>
   </tr>
 </table>
diff --git a/module/extension/view/uninstall.html.php b/module/extension/view/uninstall.html.php
index 962ce178f1..37dfe178f6 100644
--- a/module/extension/view/uninstall.html.php
+++ b/module/extension/view/uninstall.html.php
@@ -14,16 +14,24 @@
 <table class='table-1'>
   <caption><?php echo $header->title;?></caption>
   <tr>
-    <td valign='middle'>
-      <?php
-      echo "<h3 class='a-center success'>{$header->title}</h3>";
-      if($removeCommands)
-      {
-          echo "<p class='strong'>{$lang->extension->unremovedFiles}</p>";
-          echo join($removeCommands, '<br />');
-      }
-      echo "<p class='a-center'>" . html::commonButton($lang->extension->viewAvailable, 'onclick=parent.location.href="' . inlink('browse', 'type=available') . '"') . '</p>';
-      ?>
+  <td valign='middle'>
+    <?php
+    if($return->return == 'fail')
+    {
+        echo $return->removeCommands;
+    }
+    else
+    {
+        echo "<h3 class='a-center success'>{$header->title}</h3>";
+        if($return->removeCommands)
+        {
+             echo "<p class='strong'>{$lang->extension->unremovedFiles}</p>";
+             echo join($retrun->removeCommands, '<br />');
+        }
+        echo "<p class='a-center'>" . html::commonButton($lang->extension->viewAvailable, 'onclick=parent.location.href="' . inlink('browse', 'type=available') . '"') . '</p>';
+    }
+
+    ?>
     </td>
   </tr>
 </table>