A method for supporting a handover in a broadband wireless access communication system including an MSS, a serving BS providing service to the MSS, and a plurality of neighbor base stations, in which each of the BSs includes cells using different sub-channel bands. The method includes: measuring, by the BSS, intensities of signals received from the BSs, transmitting to the serving BS a request for a handover based on the measured signal intensities, establishing a connection with a target BS, to which a handover of the MSS is requested, from among the neighbor BSs before terminating a connection with the serving BS, and performing a soft handover by establishing a simultaneous connection with the two BSs in a handover area. The serving BS and the target BS allocate the same sub-channel including the same sub-carriers to the MSS when the mobile subscriber station performs the soft handover.