Abstract: Multi-hop infrastructure wireless mesh networks offer increased reliability, coverage, and reduced equipment costs over their single-hop counterparts, wireless local area networks. Equipping wireless routers with multiple radios further improves the capacity by transmitting over multiple radios simultaneously using orthogonal channels. A good channel-diverse routing is essential for throughput optimization of mesh clients and can alleviate potential congestion on any gateways to the Internet, thereby improving per-client throughput. In order to efficiently utilize the multiple channels in wireless mesh networks, a new path metric ERC(expected residual capacity) is designed, which considers multiple factors including channel-diversity, bandwidth and interference. The ERC path metric gives a good evaluation of path quality and can be used to choose paths with high throughput and low interference. Combined with the idea of multipath routing, a corresponding load-balancing routing for the multi-channel wireless mesh networks is proposed. The routing algorithm seeks several optimum paths for each traffic and then distributes the traffic among those paths as balanced as possible, which improves the communication qualities effectively. The simulation results show that by using the proposed load-balancing routing, the aggregate network throughput surpasses the single channel networks far away and obviously outperforms the common multi-channel routing. Besides, the network delay and the packet drop probability also get significant decrease.