A method for processing a handover procedure by a user equipment (UE) in a mobile communication system. The method includes receiving, by the UE, a radio resource reconfiguration message from a base station; recognizing, by the UE, a handover type based on a handover type indicator included in the received radio resource reconfiguration message; and performing, by the UE, a first or second handover procedure according to the recognized handover type. The first or second handover procedure is performed if the radio resource reconfiguration message includes mobility related information. The mobility related information includes a target physical cell identity and a new cell-radio network temporary identifier (C-RNTI).