json的key值为\u5317\u4eac这种编码，怎么获取？

json的key值为\u5317\u4eac这种编码，怎么获取？

　var json={"memo":"{\"\u57ce\u5e02\":\"\u5317\u4eac\",\"\u8054\u7cfb\u7535\u8bdd\":\"999\",\"\u5730\u5740\":\"\u8bf4\u8bf4\u51e0\u53f7\u653e\u5047\u554a\",\"\u90ae\u7bb1\":\"\",\"\u7b80\u4ecb\":\"\u8bf4\u8bf4\u51e0\u53f7\u653e\u5047\u554a\",\"\u7ecf\u8425\u8303\u56f4\":\"\u5a5a\u5e86\"}","name":"\u5a5a\u793c\u7eaa","user_id":24,"logo_path":"merchant_logo/101376049270.jpg","license_path":"image_license/101376049270.jpg","city":"\u5317\u4eac","email":"","pid":1};json.memo=eval('('+json.memo+')');alert(json.memo['简介']);alert(JSON.stringify(json.memo));这全是英文简答，我费了很大功夫。