By means of mobile communication technology such as location based services (LBS), mobile service providers can collect user's personal information more easily, which has aroused users'serious concern with their privacy. This will affect users' acceptance of mobile commerce. Thus it is necessary to examine the components of privacy concern and its effect on user behavior under the mobile commerce environment. We conduct data analysis with SEM and found out that privacy concern as a second order factor consists of four dimensions: information collection, improper access, information error and secondary usage. Privacy concern significantly affects user risk perception and trust, and through them indirectly affected usage behavior. Thus, mobile service providers need to take effective measures to alleviate users' privacy anxiety. The authors argue that their adoption behavior can be promoted to facilitate the success of mobile commerce implementation. 