The guiding paradigm of this study is the “active audience theory paradigm”, which aims to study the self-identity construction of Japanese Animation, Comic and Game(generally referred to ACG) fans as active consumers in Chinese mainland. The fans who go deep into the ACG cultural circle are obviously different from the ordinary audience. ACG fans are first fascinated by a specific text in the ACG cultural circle through their personal watching behavior, and such fascination turns from unconsciousness to consciousness. In this process, these fans actively find ways to seek self-identity and begin to understand the wider ACG cultural circle. Finally, fans will participate in the fan community, become deepgoing readers of ACG cultural circle, and complete the building of self identity. In the process of building self-identity, the initiative of fans is reflected. As a result, ACG fan community maintains long-term vitality and development potential because of such initiative of fans.