IEEE 802.16j is an amendment to the IEEE 802.16 broadband wireless access standard to enable the operation of multi-hop relay stations (RS). The relays of IEEE 802.16j include transparent relay and non-transparent relay with scheduling function located in the base station (centralized scheduling) or in the relay station (distributed scheduling). IEEE 802.16j aims to enhance the coverage, user throughput and system capacity of IEEE 802.16e. In this paper we consider one of the MMR situations: fixed relay in two-hop networks and the select algorithm is distributed controlled by Base Station of MMR (MR-BS). We propose a cooperative relay selection algorithm based on signal intensity. In the algorithm, the BS selection the optimal cooperative relay node according to gathering the parameters of relay link and access link. The simulation results show that the proposed algorithm can effective increases user capacity as well as improving system performance.