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 downlink frequency band into a plurality of frequency partitions, allocating one or more subbands in a certain frequency partition among the plurality of frequency partitions to the MBS data, and c) allocating one or more subbands in each remaining frequency partitions one by one to the MBS data, if the number of subbands required for transmitting the MBS data (KSB,E MBS) is larger than the number of subbands in the certain frequency partition.