In an open Web service environment, it is difficult to guarantee the authenticity of the feedback ratings reported by users after they have already consumed some services, which leads to large deviation between evaluation results and actual values of service reputation. Therefore, there are much more failures in service selection. To address the above problem, this paper proposes a reputation evaluation approach for Web service selection. The main idea of the proposed approach is evaluating the reputation by three reputation evaluation model including feedback checking, feedback adjustment, and feedback detection. Simulation results demonstrate the proposed approach not only improves the objectivity of reputation evaluation effectively, but also reduces the deviation of service selection significantly.