The present invention provides a mobile communication system in which a target Radio Network Controller can decide the PtP method or PtM method correctly, and notify that the contents data of an MBMS service starts to be transferred to the radio terminal. A source Radio Network Controller sets up the relevant information of the MBMS service joined by a radio terminal in a Relocation Required message, and transmits it to an SGSN4. The SGSN4 transmits a Relocation Request message to the target Radio Network Controller. The target Radio Network Controller sets up the radio resources to perform the communication with the radio terminal, and stores the relevant information of the MBMS service in the Relocation Required message in memory.