diff --git a/cocos2dx/support/ccUTF8.cpp b/cocos2dx/support/ccUTF8.cpp
index 53d90b13d6..963d5cd2c4 100644
--- a/cocos2dx/support/ccUTF8.cpp
+++ b/cocos2dx/support/ccUTF8.cpp
@@ -275,7 +275,7 @@ cc_utf8_get_char (const char * p)
 }
 
 
-unsigned short* cc_utf8_to_utf16(const char* str_old, size_t length/* = -1 */, size_t* rUtf16Size/* = NULL */)
+unsigned short* cc_utf8_to_utf16(const char* str_old, int length/* = -1 */, int* rUtf16Size/* = NULL */)
 {
     int len = cc_utf8_strlen(str_old, length);
     if (rUtf16Size != NULL) {
diff --git a/cocos2dx/support/ccUTF8.h b/cocos2dx/support/ccUTF8.h
index e8799e8733..87c7a465b8 100644
--- a/cocos2dx/support/ccUTF8.h
+++ b/cocos2dx/support/ccUTF8.h
@@ -59,7 +59,7 @@ CC_DLL std::vector<unsigned short> cc_utf16_vec_from_utf16_str(const unsigned sh
  *
  * Return value: the newly created utf8 string.
  * */
-CC_DLL unsigned short* cc_utf8_to_utf16(const char* str_old, size_t length = -1, size_t* rUtf16Size = NULL);
+CC_DLL unsigned short* cc_utf8_to_utf16(const char* str_old, int length = -1, int* rUtf16Size = NULL);
 
 /**
  * cc_utf16_to_utf8:
diff --git a/scripting/javascript/bindings/ScriptingCore.cpp b/scripting/javascript/bindings/ScriptingCore.cpp
index 2a2f32ad70..f10ae9da45 100644
--- a/scripting/javascript/bindings/ScriptingCore.cpp
+++ b/scripting/javascript/bindings/ScriptingCore.cpp
@@ -1530,7 +1530,7 @@ jsval c_string_to_jsval(JSContext* cx, const char* v, size_t length /* = -1 */)
         return JSVAL_NULL;
     }
     jsval ret = JSVAL_NULL;
-    size_t utf16_size = 0;
+    int utf16_size = 0;
     jschar* strUTF16 = (jschar*)cc_utf8_to_utf16(v, length, &utf16_size);
 
     if (strUTF16 && utf16_size > 0) {