This thesis aims to explore how fans use social media to participate in activities relatedto the idol, and what is the level of participation of different fans in the fan group. Thisthesis used qualitative research methods – online observations and semi-structured indepth interviews to collect the empirical data, through focusing on the fan group of KrisWu. The theories of Jenkins and Carpentier are also applied to explore and describe theparticipatory practices of fans. By employing the theory of Jenkin’s participatoryculture to the first part of the analysis, the research results show that for the fans, socialmedia plays an important role in their participation, providing fans with a newenvironment to communicate and organize activities. Fan activities can be categorizedinto three major types: online consumption behaviors, fan text productions, and onlinesupporting activities. By applying the political and critical approach of participation, aswell as Carpentier’s four-level analytical model to the second part of the analysis, thisstudy finds that there are three sub-processes related to online fan communities – themanagement subprocess, the activity organization subprocess, and the subprocess oftext production and distribution. In each fan group, there are four different roles of fans– leaders, creators, supporters, and less active fans. Besides, through analyzing theidentities and decision-making moments, it can be said that although each fan isrelatively equal in the whole participatory process, there are still certain power relationsbetween each role of fans, especially in the process of fan group management.