A multicast communication method for relaying a multicast packet from a first member node to a plurality of second member nodes in a wireless network is provided, wherein the first member node and the second member nodes belong to a same group and can communicate with each other via a plurality of non-member nodes. In the multicast communication method, a number and distances of the second member nodes are recorded. The multicast packet is received from the first member node, and a waiting time is determined according to the number and the distances of the second member nodes. Whether the multicast packet is broadcasted by any other relay node is monitored during the waiting time. If the multicast packet is already broadcasted to all the second member nodes by other relay node, the multicast packet is not broadcasted; otherwise, the multicast packet is broadcasted after the waiting time elapses.