This study investigated the effects of grouping strategy based on group members’ self-regulated learning skill level on group self-regulation, group performance, and group activity satisfaction. In the fall semester of 2010, 93 college-level students, who were taking a general course in which project-based collaborative learning was applied, participated in this study. At the very beginning of the semester, each participant’s self-regulation level was measured, and then the participants were divided into high, medium, and low self-regulation levels. Then, based on the self-regulation level, four different group types were composed; heterogeneous group, high group, medium group, and low group. The ANOVA results revealed that the low groups were lower than heterogeneous, high, and medium groups in group self-regulation level. The heterogeneous groups performed significantly better than the other three homogeneous groups. The heterogeneous and high groups were more satisfied with group activity than the low groups. Finally, the level of group self-regulation positively correlated with group performance and group activity satisfaction. This study emphasizes the importance of group members’ self-regulation level in group composition which should be considered by instructors to promote effective collaboration.