In wireless ad hoc networks, collisions and congestion at some nodes cause degradation of network throughput. There have been some load-aware routing protocols proposed for load distribution and balancing by detouring congested nodes. However, they are for unicast communication. This paper proposes a load-aware protocol for the same purpose in multicast communication. The protocol has features to build a multicast tree with load distribution and balancing, and to reorganize the tree according to dynamic load changes. Simulation-based preliminary experiments result in that the number of highly loaded members in a multicast tree was smaller with the proposed protocol than that with a conventional one. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.