Social support is often related to successful problem-solving and enhanced achievement. However, limited research on it has been conducted in collaborative learning settings, where research attention has been primarily placed on sophisticated technologies and cognitive domains. Considering existing problems in collaborative learning, including low levels of individual accountability and free rider issues, and the importance of social support and coopetition for collaborative learning, this study investigated the effect of coopetition designs on the development of social support in collaborative learning. A quasi-experiment was conducted in the naturalistic learning setting to explore effects of zero-sum coopetition, social-comparison coopetition, and the collaboration-only design on three subscales of social support (emotional, esteem, and informational social supports). The findings indicated that the two coopetition designs surpassed the collaboration-only design in strengthening social support and academic performance. Social-comparison coopetition further outperformed zero-sum coopetition.