Method of transmitting multimedia broadcast/multicast service in IP wireless access network

The present invention discloses a method which issues a multi-media broadcast or multicast serving (MBMS) service in an IP radio access network (RAN). The method comprises that a radio network controller sends sending control information to a correspondent base station, and the base station issues the (MBMS) service data from the radio network controller and sent in a multicast form at the Iub interface according to the received sending control information. Since the MBMS service data is issued by adopting the multicast form in an IP bearing network, for the same MBMS service, the radio network controller just needs to issue once to all the base stations, the base station gets the MBMS service data from the assigned position in the network according to the received sending control information, and the MBMS service data is issued through an appointed channel which is used to send the MBMS service data at the correspondent primary area. In this way, for the same MBMS service data, the RNC just needs to issue once to all the NodeB which are controlled by the radio network controller (RAN). The bandwidth of the Iub interface is greatly saved, the burden of the network is lightened, and the investment of the operator is reduced.