This study is designed to exam what role new media exactly plays in the process of collective identity construction. Qidong Event is selected as the case and is divided into two periods: environmental movement and civil rights movement. With frame analysis by Goffman, this paper represents the construction process of collective identity by the analysis of news report and netizen opinion on new media in the two periods. Four main roles new media plays in this process are identified through this study: categorizing, wakingup, producing collective memory, producing and reproducing ideology and promoting the competition between different discourses. These roles present in aggregation, integration and stabilization periods of identity construction. It is highly suggested that further discussion on this issue be diverted to class, personal interests, cultural factors etc.