Disclosed is a method for supporting a handover in a broadband wireless access communication system which includes a mobile subscriber station, a serving base station currently providing service to the mobile subscriber station, and a plurality of adjacent base stations different from the serving base station, in which each of the base stations includes cells using subchannel bands different from each other, the method including establishing a set of base stations which currently provide wireless channels for data transmission/reception to the mobile subscriber station; classifying, by each base station, entire subchannels into a plurality of sets of subchannels; and allocating each of the sets of subchannels obtained by the classification to a PUSC (Partial Usage of Subchannels) subchannel area of each sector, wherein, every base stations included in an active set select an equal number of PUSC subchannels from among a PUSC subchannel area allocated to each of the base stations and allocate the selected PUSC subchannels to the mobile subscriber station, and the mobile subscriber station receives a downlink signal transmitted through each of PUSC subchannel areas and performs a predetermined combining of all signals received from each of the BSs.