WeChat is a mobile text and voice messaging communication service developed by Tencent in China, first released in January 2011. WeChat provides multimedia communication with text messaging, hold-to-talk voice messaging, broadcast (one-to-many) messaging, photo/video sharing, location sharing and contact information exchange. There are more than 600 million WeChat users in the world. The paper discusses  WeChat development from users’ amount, market scale and the function improvement. The author analyzes the characteristic, social functionand therisk of WeChat communication by quantitative research. The author finds  Chinese deem Wechat information is most credible. Credibility of Wechat, microblog,webnews,newspaper,broadcastandTV in China are respectively 63.4%、38.6%、21.7%、19.6%、14.6%、33.9%.