Since multi-radio multi-channel wireless mesh networks are widely brought into use, the channel assignment scheme plays a critical role in determining the performance of wireless mesh networks. Nowadays many channel assignment schemes have been proposed to enhance the performance of the wireless networks. However, most of the existing schemes assume that all the interference links induce the same level of interference on the target link, which will lead to poor network performance as the assumption deviates from the actual situation. In this paper, we propose a novel clique-based clustering channel assignment (CCCA) scheme which takes different levels of interfering links into consideration. By locally calculating maximum cliques in the interfering graph, CCCA logically partitions the networks into clusters and executes channel assignment in three stages to minimize interference of links including both non-coordinated interference and coordinated interference. The simulation results demonstrate that CCCA can significantly increase the network throughput, improve the fairness of network capacity distribution and decrease the end-to-end delay, which enhances the performance of the wireless mesh networks effectively.