diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82612333..d8400ccf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 #CHANGELOG
 
+## v2.4.3
+
+2013-02-17
+
+Issue [#52](https://github.com/qiniu/nodejs-sdk/pull/52):
+
+- 去除对自定义 generateQueryString() 函数的依赖，使用 querystring 包的 stringify() 函数。
+
 ## v2.4.2
 
 Issue [#48](https://github.com/qiniu/nodejs-sdk/pull/48):
diff --git a/lib/rs.js b/lib/rs.js
index 2e12d51e..3c306483 100644
--- a/lib/rs.js
+++ b/lib/rs.js
@@ -3,6 +3,7 @@ var path = require('path');
 var crc32 = require('crc32');
 var mime = require('mime');
 var formstream = require('formstream');
+var querystring = require('querystring');
 var config = require('./conf.js');
 var util = require('./util.js');
 var img = require('./img.js');
@@ -135,7 +136,7 @@ Service.prototype.uploadWithToken = function(uploadToken, stream, key, mimeType,
       "mime_type": mimeType
     };
   }
-  var callbackQueryString = util.generateQueryString(callbackParams);
+  var callbackQueryString = querystring.stringify(callbackParams);
   var url = config.UP_HOST + "/upload";
 
   var filename = path.basename(key);
diff --git a/lib/util.js b/lib/util.js
index bc81a9dc..387c149d 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -34,21 +34,6 @@ exports.generateActionString = function(bucket, key, mimeType, customMeta, crc32
   return actionParams;
 }
 
-exports.generateQueryString = function (params) {
-  if (params.constructor === String) {
-    return params;
-  }
-  var total_params = [];
-  for (var key in params) {
-    total_params.push(escape(key) + "=" + escape(params[key]));
-  }
-  if (total_params.length > 0) {
-    return total_params.join("&");    
-  } else {
-    return "";
-  }
-}
-
 // ------------------------------------------------------------------------------------------
 // func readAll
 
diff --git a/package.json b/package.json
index 868e5802..290ec119 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "qiniu",
-  "version": "2.4.2",
+  "version": "2.4.3",
   "description": "Node wrapper for Qiniu Resource (Cloud) Storage API",
   "main": "index.js",
   "directories": {