A method of allocating resources in a wireless communication system is provided. A wireless device which makes a transition between Low Power Consumption (LPC) mode and active mode receives, from a base station, an allocation message for allocating persistent scheduling resources used in persistent scheduling. The wireless device communicates with the base station using the persistent scheduling resources, for active duration in which the wireless device operates in the active mode. The wireless device deallocates the persistent scheduling resources automatically when the active duration is finished.