Provided are a method for a user equipment (UE) to transmit a medium access control protocol data unit (MAC PDU) in a wireless communication system, and an apparatus supporting the same. The method may include: receiving information on priorities of semi persistent scheduling (SPS) configurations, from a base station; selecting a first carrier among the multiple carriers, based on the information on priorities of the SPS configurations; allocating a resource of the selected first carrier to a logical channel with the highest priority; and transmitting the MAC PDU, by using the resource of the selected first carrier.