diff --git a/install/common.php b/install/common.php
index aef66a632..dbbe0e0af 100644
--- a/install/common.php
+++ b/install/common.php
@@ -6,7 +6,7 @@
 
 function lang(){
   $lang = $_REQUEST['lang'] ? $_REQUEST['lang'] :"zh";
-  if ($lang == 'zh-CN') {
+  if ($lang == 'zh') {
     return include("lang.".$lang.".php");
   }
   if ($lang == 'en') {
@@ -87,4 +87,4 @@ function replace_file_content($file , $from ,$to ){
   if ($content2) {
       file_put_contents($file,$content2);
   }
-}
\ No newline at end of file
+}