The present invention relates to a wireless communication system, and more particularly, to a method for allocating a resource for multicast and/or broadcast service data in a wireless communication system and apparatus therefore. The present invention includes the steps of dividing a certain frequency band into a plurality of subbands, and allocating at least one subband to the MBS data from a subband having a lowest index among the plurality of subbands, wherein the MBS data is multiplexed with unicast data.