Online learning communities are an important means of sharing and creating knowledge. Online behaviors and online roles can reveal how online learning communities function. However, no study has elucidated the relationships among online behaviors, online roles, and online learning communities. In this study, 32 preservice teachers participated in an 18-week instruction program. Analyses of online group discussions revealed the following: (a) of thirteen identified online behaviors, the most common were constructing a positive atmosphere, providing opinions for group assignments, and providing reminders of assignment-related work; (b) of eight online roles identified within a group, the most common roles were information providers, opinion providers, and troublemakers; (c) four online learning communities based on "collaboration" and "participation" were identified. The evolution of these online learning communities indicates the interrelationships among online behaviors, roles, and learning communities. (Contains 7 tables and 2 figures.)