Because the Internet provides an alternative forum for the social interaction of professional groups, understanding how these groups form as virtual communities (VCs) in cyberspace is crucial. In this study, we observe the social interactions of teachers belonging to the largest VC in Taiwan and analyze discourse on an important educational policy, using content analysis to ascertain how virtual group identity is established. Our primary findings show that among the seven identity categories characterizing professional virtual group identity, both alliance and kinship types of identities are the main forces behind the formation of a virtual group. In contrast, the affection, attachment, bonding, closeness, and nostalgia types of identities show minimal effect. Moreover, leadership of the virtual group plays a critical role in the group setting, and participants play a part in restoring a positive sense of self or in shaping the group identity as they encounter threats in this dynamic environment.