Pervasive computing is becoming an emerging paradigm of computing, however currently there is little work addressing pervasive computing model. The goal of this paper is to model a pervasive computing environment as a user-centric “SmartShadow” using the BDP (Belief-Desire-Plan) user model, which maps pervasive computing environments into a dynamic virtual user space. In the BDP model, desires of a user are inferred from his belief set, and plans are made to satisfy each desire. Pervasive services are used to describe computing capabilities of the cyberspace, which can be organized by the user’s BDP to accomplish his/her desires. A composition process casts pervasive services into a user’s SmartShadow. The SmartShadow will follow a user to provide the user with pervasive services, like one’s shadow in the physical world. The proposed model is logically natural, and can flexibly deal with dynamics of pervasive computing spaces. This paper also implements a simulation system to evaluate the SmartShadow model.