Many different applications are concentrating on collecting information about users. The main purpose of this information collection is to enable the applications of understanding the users, their preferences and their interests in order to provide them with personalized services. For these reasons, different applications in several areas organize user properties, preferences and interests based on a user model, a structure holding all relevant user-related information. Thus, the issue of user modeling is being tackled by researchers attempting to propose valuable structure and to provide adaptable applications to use it successfully. However, the most of published studies are focused on centralized user model. In this sense, we propose a Generic Context-aware Model (GCAPM) in peer-to-peer (P2P) environment. We illustrate the use of the model in the context of a case study, focusing on query expansion