Aiming at the bandwidth capacity problem in the wireless mesh networks, based on wireless network interfere protocol model for measuring wireless link interference, the paper formulates the channel assignment problem of finding the channel assignment scheme as integer linear program and proposes a channel assignment heuristic algorithm by using objective function for optimizing channel assignment in order to minimize the overall network interference weight during assigning channels to wireless communication links in the wireless mesh networks. Simulation results show that network throughput can be improved significantly by the proposed algorithm.