A method of signaling bearer connection on Iu interface for MBMS service, includes the following steps: (a) RNC receives a MBMS Notification message for a certain MBMS service from SGSN; (b) RNC constructs a MBMS Service Request message according to the contents of the notification; (c) RNC sends a SCCP Connection Request message to SGSN, requests to establish a SCCP signaling connection, and then waits for a reply; (d) RNC receives a SCCP Connection Confirmation message from SGSN. This invention solves the problem of signaling connection on Iu interface after MBMS service is introduced into the existing mobile communication system. The connection mode provided in this invention can reasonably utilize network resources, effectively reduce signaling congestion on Iu interface and reduce modifications to the existing Iu interface message.