Social commerce is a new type of electronic commerce which uses social networks to facilitate social interactions and user contributions. Since social commerce is still in its early development, there is lack of theoretical model to analyze what factors may affect people’s intention to participate in social commerce. The purpose of this research is to propose a theoretical model to analyze user adoption behavior with the consideration of perceived benefit, perceived risk, and trust believes from both commerce and social networks perspective. The model will be empirically tested through an online user survey. This dual-perspective model may also be extended to study user adoption behavior in new types of e-healthcare or e-government system with strong social network connections.