Because of its relative simplicity and low overhead, overlay multicasting for MANET has been widely explored all over the world. By now, many overlay multicast protocols for MANET has been proposed. But most of these protocols aim only at improving the efficiency and ignore the dynamic and unreliable nature of MANET. Their performance usually degrades when these protocols are put into practice. In this paper, we propose a new overlay multicasting protocol, AREMP. In our protocol, we take full consideration of the dynamic nature of the network and try to improve both the reliability and the efficiency. Our simulation shows that our protocol can get a good balance between reliability and efficiency.