By social network analysis, users can know how information flows through social ties, how people acquire information and resources, and how cleavages and coalitions operate. In this research, based on social network theories, we develop a social network analysis system to facilitate teams? collaboration and then evaluate the system?s performance. The system can draw graphs to present a team?s social networks both ego-centered and whole network, and calculate the values of attributes characterizing the social network. The resulting system can facilitate understanding for both team leaders and general members and help them to see relations and interaction patterns of their teams. The evaluation results indicate that the social network analysis is acceptable by users in terms of simplicity, utility, certainty, and novelty for developing virtual teams of a cyber community.