Abstract: According to the characters of Ad hoc networks, a multipath source routing algorithm based on network coding is presented. The algorithm refers the idea of COPE. In realization, the multiple paths that have maximum coding opportunity are found by caching short paths in medium nodes and labeling the medium nodes that have coding opportunity. Because network coding reduces data's transmission times, the algorithm can improve channel utilization effectively. Simulations under NS2 environment prove that the new algorithm has better performance in balancing the network load and improving network throughput.