Abstract: This study tries to answer these questions： Why do activists emerge during the Chinese urban community elections? What are the structural characteristics of this social group? What is their action logic in their community? Through participation observation， semistructured interviews， and content analysis， the study came to the following conclusions： The activists in the urban communities， with the building leaders (louzuzhang) being the core， pursue for social reward； and how much of the social reward can be obtained determines how active they get involved in the community activities. The network of the activists who are in pursuit of social reward has become an important mechanism in the governance of current Chinese urban communities.

Key words: activists, building leaders (louzuzhang), community election, social reward