This article explores members’ psychological mechanism for participating in microblogs community, with the application of methods of multiple regression and path analysis. It shows that members’ perception of the credibility of microblogs content and self-presentation are two important psychological processes. Furthermore, the impacts of members’ motivations of self-representation, informational value, entertainment value and social enhancement on their behaviors for participating in microblogs community are both mediated by the variables of the perception of the credibility of microblogs content and self-presentation. The conclusions have some practical significances in managing microblogs community and guiding public opinion for microblogs service providers and government departments.