An apparatus and method for controlling a Hybrid Automatic Repeat reQuest (HARQ) operation in a transmitter of a wireless mobile communication system using each frame constituted by a plurality of subframes are provided. In the method for controlling an HARQ operation, indication information indicating a subframe position where transmission of a data burst starts and the number of subframes required for transmission of the data burst is transmitted to a receiver through an i-th frame. When the number of subframes does not exceed a threshold, it is determined that the data burst at the subframe position indicated by indication information of an (i+1)-th frame is retransmitted to the receiver. When the number of subframes exceeds the threshold, it is determined that the data burst at the subframe position indicated by indication information of an (i+n)-th frame, where n is a positive integer exceeding 1, is retransmitted to the receiver.