—Community of web services (CWS) is a society composed by a number of functionally identical web services. The communities always aim to increase their reputation level in order to obtain more requests. In this paper, we propose an effective mechanism dealing with reputation assessment for communities of web services. The proposed mechanism is based on after-service feedbacks provided by the users to a run-time logging system. The proposed method defines the evaluation metrics involved in reputation assessment of a community, and supervises the logging system in order to verify the validity and soundness of the feedbacks provided by the users. In this paper, the proposed framework is described, a theoretical analysis of its assessment and its implementation along with empirical result discussions are provided. We also show how our model is efficient, particularly in very dynamic environments. Keywords-Web Service; Community; Reputation;