Abstract: Congestion control is key problem in designing multicast protocols. The merits and shortcomings of sender-drivered and receiver-drivered in congestion control are analyzed respectively. Then a congestion control mechanism for multicast, RBMCC that is rate-based and drivered mixedly by sender and receiver, is presented. In RBMCC, each receiver estimate its packet loss rate respectively and send ACKs to its parent, intermediate nodes aggregated these ACKs that come from all of children. TCP-friendly rate computed by sender provide timely and accurate response to the network congestion. The results of experimental simulation show that RBMCC is quite flexible with satisfactory equality.