Language is an important semiotic system. The nature of interaction is the communication and exchanges of information. Speech act refers to the fact that people use language to do something. Speech act theory originated with the British philosopher John Austin. Researches on speech act start with the study on the functions of language in daily life. Until now so many scholars conduct researches on the daily language based on speech act theory. With the development of mass media, people tend to use Internet more and more frequently. As a result, the Internet becomes an important part in people’s daily life. People use the Internet to learn, to socialize and to have fun. Media discourse is a complex system which consists of diverse categories. Nowadays, WeChat as a kind of mass media is popular. This article will conduct a research on the titles of articles in WeChat based on the speech act theory. Meanwhile, some feasible suggestions on how to write a good title are put forward.