diff --git a/lib/front/front.class.php b/lib/front/front.class.php
index 289ec24322..af5c0fe230 100644
--- a/lib/front/front.class.php
+++ b/lib/front/front.class.php
@@ -568,6 +568,8 @@ EOT;
      */
     static public function exportConfigVars()
     {
+        if(!function_exists('json_encode')) return false;
+
         global $app, $config, $lang;
         $defaultViewType = $app->getViewType();
         $themeRoot       = $app->getWebRoot() . 'theme/';
diff --git a/module/install/control.php b/module/install/control.php
index 144962b1db..57ace64e4e 100644
--- a/module/install/control.php
+++ b/module/install/control.php
@@ -54,6 +54,7 @@ class install extends control
         $this->view->phpResult      = $this->install->checkPHP();
         $this->view->pdoResult      = $this->install->checkPDO();
         $this->view->pdoMySQLResult = $this->install->checkPDOMySQL();
+        $this->view->jsonResult     = $this->install->checkJSON();
         $this->view->tmpRootInfo    = $this->install->getTmpRoot();
         $this->view->tmpRootResult  = $this->install->checkTmpRoot();
         $this->view->dataRootInfo   = $this->install->getDataRoot();
diff --git a/module/install/lang/en.php b/module/install/lang/en.php
index e7635f206d..c2a81c1512 100644
--- a/module/install/lang/en.php
+++ b/module/install/lang/en.php
@@ -58,6 +58,8 @@ $lang->install->pdo          = 'PDO extension';
 $lang->install->pdoFail      = 'Edit the php.ini file to load PDO extsion.';
 $lang->install->pdoMySQL     = 'PDO_MySQL extension';
 $lang->install->pdoMySQLFail = 'Edit the php.ini file to load PDO_MySQL extsion.';
+$lang->install->json         = 'JSON extension';
+$lang->install->jsonFail     = 'Edit the php.ini file to load JSON extension';
 $lang->install->tmpRoot      = 'Temp directory';
 $lang->install->dataRoot     = 'Upload directory.';
 $lang->install->mkdir        = '<p>Should creat the directory %s。<br /> Under linux, can try<br /> mkdir -p %s</p>';
diff --git a/module/install/lang/zh-cn.php b/module/install/lang/zh-cn.php
index 1103ce7aa4..391395184f 100644
--- a/module/install/lang/zh-cn.php
+++ b/module/install/lang/zh-cn.php
@@ -58,6 +58,8 @@ $lang->install->pdo          = 'PDO扩展';
 $lang->install->pdoFail      = '修改PHP配置文件，加载PDO扩展。';
 $lang->install->pdoMySQL     = 'PDO_MySQL扩展';
 $lang->install->pdoMySQLFail = '修改PHP配置文件，加载pdo_mysql扩展。';
+$lang->install->json         = 'JSON扩展';
+$lang->install->jsonFail     = '修改PHP配置文件，加载JSON扩展。';
 $lang->install->tmpRoot      = '临时文件目录';
 $lang->install->dataRoot     = '上传文件目录';
 $lang->install->mkdir        = '<p>需要创建目录%s。<br /> linux下面命令为：<br /> mkdir -p %s</p>';
diff --git a/module/install/model.php b/module/install/model.php
index 47cd6d5428..f755cd9335 100644
--- a/module/install/model.php
+++ b/module/install/model.php
@@ -88,6 +88,17 @@ class installModel extends model
         return $result = extension_loaded('pdo_mysql') ? 'ok' : 'fail';
     }
 
+    /**
+     * Check json extension.
+     * 
+     * @access public
+     * @return string   ok|fail
+     */
+    public function checkJSON()
+    {
+        return $result = extension_loaded('json') ? 'ok' : 'fail';
+    }
+
     /**
      * Get tempRoot info.
      * 
diff --git a/module/install/view/step1.html.php b/module/install/view/step1.html.php
index 92081f3fc7..ee0a07898b 100644
--- a/module/install/view/step1.html.php
+++ b/module/install/view/step1.html.php
@@ -36,6 +36,12 @@
     <td class='<?php echo $pdoMySQLResult;?>'><?php echo $lang->install->$pdoMySQLResult;?></td>
     <td class='a-left f-12px'><?php if($pdoMySQLResult == 'fail') echo $lang->install->pdoMySQLFail;?></td>
   </tr>
+  <tr>
+    <th><?php echo $lang->install->json;?></th>
+    <td><?php $jsonResult == 'ok' ? printf($lang->install->loaded) : printf($lang->install->unloaded);?></td>
+    <td class='<?php echo $jsonResult;?>'><?php echo $lang->install->$jsonResult;?></td>
+    <td class='a-left f-12px'><?php if($jsonResult == 'fail') echo $lang->install->jsonFail;?></td>
+  </tr>
   <tr>
     <th><?php echo $lang->install->tmpRoot;?></th>
     <td>