diff --git a/cocos2dx/support/CCUserDefault.cpp b/cocos2dx/support/CCUserDefault.cpp
index 57a246d261..f956146e2e 100644
--- a/cocos2dx/support/CCUserDefault.cpp
+++ b/cocos2dx/support/CCUserDefault.cpp
@@ -368,6 +368,12 @@ bool CCUserDefault::createXMLFile()
 		bRet = true;
 	} while (0);
 
+	// if doc is not null, free it
+	if (doc)
+	{
+		xmlFreeDoc(doc);
+	}
+
 	return bRet;
 }