A system and method for relaying Multicast Broadcast Service (MBS) are provided. The system for relaying MBS includes a base station; and a plurality of relay stations, wherein the relay stations forms multi-hop relay network, and wherein the base station selects a Modulation and Coding Scheme (MCS) level among a plurality of MCS levels based on channel condition between the base station and the respective relay stations. The MBS relay system of the present invention provides improved data throughput and stable broadcast services.