Various application services including multimedia applications need efficient multicast technologies, but the IEEE 802.11 protocol, which is currently the most widely used, does not specify the standard on multicast, which is, instead, substituted by broadcast or a combination of unicast. Using broadcast is, however, difficult to judge on the transmission success or fail, because it does not receive acknowledgements for each data transmission. Using unicast, on the other hand, has problems of transmission delay or bandwidth waste due to the duplicate transmission or retransmission. This paper proposes a RBMAC that guarantees a reliable multicast and improves the throughput by using busy-tone. The proposed RBMAC is implemented in the ns-2 simulator and performed various comparisons with the multicast with IEEE 802.11 MAC. The simulation results show that the proposed RBMAC improves the throughput as much as 20% and the receiving rate by up to 49%.