The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing a Packet filtering for ProSe in a D2D communication system, the method comprising: configuring a plurality of identifiers of the UE; receiving, by a Medium Access Control (MAC) entity, a Medium Access Control Protocol Data Unit (MAC PDU) including an indicator; checking, by the MAC entity, whether the indicator is equal to 16 Most Significant Bit (MSB) of any of identifiers of the UE; and delivering the MAC PDU, to a Radio Link Control (RLC) entity, after successfully decoding the MAC PDU, if the indicator is equal to 16 MSB of any of identifiers of the UE.