A method for providing concurrent service in a mobile communication system is disclosed in which a SCCP connection identifier SLR/DLR of a lower layer and a Service Option Connection Identifier (SOCI) on an IOS message of the higher layer to be exchanged are transmitted when a SCCP connection is established between a BSC and a MSC, thereby providing additional services to those already requested from a mobile station after the SCCP connection establishment without stopping a currently used service. According to the method, the concurrent service is provided while minimizing the conventional call processing procedures on the interface between the BSC and the MSC, thereby allowing a subscriber to use new additional service without stopping the current service or concurrently use a plurality of services such as voice and packet data services. Furthermore, a flexible confront is possible to a future development direction of the network. Providing concurrent service is an essential function of the third generation mobile communication network in a multimedia environment.