Social media is a widely accepted medium for interaction and communication. A large amount of information about health care springs out through various social medias. We Chat is a multi-function social media as well as an information sharing platform with largest users in China right now. Many We Chat accounts concentrated on showing and spreading healthcare information. They are trying to attract more readers and spread the information among them. Thus , it is important to find out what changes people ’ s behavior or attitude toward certain kind of information. This research focuses on the influence of the authority of information sources and authors as well as the format and length of information. Those four factors, compared with those in the formal studies are much more specific and much easier to be quantization especially for measurement. Lab experiment study was applied in this paper. The result comes that the authority of subscriptions and information format affect both perceived credibility and interestingness levels, while the authority of authors only makes difference to credibility level. And the length of information shows no significant influence.