A Minimizing Intermediate Multicast Routing protocol(MIMR)is proposed for dynamic multi-hop ad hoc networks.In MIMR,multicast sessions are created and released only by source nodes.In each multicast session process,the source node keeps a list of intermediate nodes and destinations,which is encapsulated into the packet header when the source node sends a multicast packet.Nodes receiving multicast packets decide to accept or forward the packet according to the list.Depending on topology matrix maintained by unicast routing,the shortest virtual hierarchy routing tree is constructed by improved Dijkstra algorithm.MIMR can achieve the minimum number of intermediate nodes,which are computed through the tree.No control packet is transmitted in the process of multicast session.Load of the network is largely decreased.Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks.