Previous researches generally regard social capital as an access to external knowledge. The implicit assumption is that social capital brings knowledge inflow to the actor. Due to the mutuality of knowledge sharing, social capital also leads to knowledge outflow to the actor in essence. The existing studies mainly emphasize knowledge inflow side because knowledge sharing in the private-based innovation network is bounded by organization boundaries and various control mechanism which effectively inhibits knowledge outflow. In common-based innovation network context, access to knowledge is free and boundaries between project teams is obscure, leading to prominent outflow of knowledge to the actor. This paper investigates the effect of team level social capital on new product popularity and how to make best use of it in the context of common-based innovation network. The data is collected from Sourceforge.net and a common-based innovation network is constructed by1595 teams and 8186 contributors. Results show degree centrality has an inverted U effect and betweenness centrality has positive effect on new product development popularity; team’s knowledge utilization ability can postpone the negative effect of social capital (degree centrality) and strength the positive effect of social capital (betweenness centrality).