Abstract: A method for creating and assigning TMGI, comprising steps of: sending a message to a SGSN when an UE joining a MBMS service group; if a MBMS TMGI has been added to SGSN records, the SGSN directly replying to the UE with the TMGI corresponding to a service; if there is no record for this service in the SGSN, the SGSN sending a message to the GGSN, and if the TMGI corresponding to this service is created by the GGSN, the GGSN sending it to the SGSN; if there is no record in the GGSN and a TMGI is created by the GGSN, the GGSN creates a TMGI for the MBMS service; e. the SGSN sending the TMGI received from the GGSN to the RNC. f. The UE receiving signal from the RNC by using the TMGI.