The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing a SPS activation in multiple SPS resources in wireless communication system, the method comprising: receiving an activation command for a first set of Semi-Persistent Scheduling (SPS) resources from a network, wherein a second set of SPS resources which is already activated on the UE; activating the first set of SPS resources and deactivating the second set of SPS resources based on the activation command for the first set of SPS resources; and transmitting a SPS confirmation Medium Access Control (MAC) Control Element (CE) which indicates that the UE successfully deactivates the second set of SPS resources and activates the first set of SPS resources, in a response to the activation command for the first set of SPS resources.