In wireless mesh networks, multicast routing is one of the supporting technologies for its practical application, and has become the research focus. Since the traditional multicast routing protocols don’t adapt themselves directly to the structure characteristic and performance requirement of wireless mesh networks, a variety of protocols for wireless mesh networks are studied. This paper summarizes the design targets, principles and classification methods for protocols. The fundamental mechanism, characteristics and performance of existing representative protocols are discussed and compared in detail. Finally, the influences of multi-radio multi-channel and multi-rate on the design of multicast routing protocol are analyzed, and the importance of establishing the cross-layer optimization model and the mechanism of the multicast routing based on actual environment and practical design are pointed out.