The resource searching efficiency is the most important performance in the hybrid Peer-to-Peer (P2P) systems. In this paper, we give the effect factors of search efficiency and its optimization methods in the hybrid P2P systems based on the analysis of evaluation criterion of search mechanism in the P2P systems. Firstly, we present the evaluation criterion of search mechanism in the aspects of users and systems, as for users, including the number of results, accuracy rate and response time, and for systems including search efficiency, scalability and robustness. Furthermore, we analyze the eff...