A system and method is provided for controlling a packet data service in a mobile communication network, in which, when a packet data service active terminal moves from an area of an old radio network controller to an area of a new radio network controller in either a suspended state or a dormant state, the same medium access control state information and the same radio resource control information are applied between the new radio network controller and the active terminal. Therefore, the packet data service can rapidly be resumed on the basis of an initially established point-to-point protocol link. If the active terminal moves from the old radio network controller to the new radio network controller under the condition that only a point-to-point protocol state is maintained between the active terminal and a packet data node, the active terminal detects a received pilot signal and checks a system overhead message. If the active terminal should perform a handoff operation in the suspended state, the active terminal requests the old radio network controller to permit its change to the dormant state or an active state.