A Base Station (BS) includes an apparatus is configured to reduce a MAP overhead in a broadband wireless communication system. The BS operation method for reducing an overhead in a broadband wireless communication system includes transmitting control information for initial transmission and changing first information among the control information transmitted at the initial transmission into second information needed at a retransmission time when there is a retransmission request for the initial transmission. The BS also transmits control information for retransmission including the second information.