An apparatus and method for feeding back hybrid automatic repeat request-acknowledgement (HARQ-ACK) information are provided. The apparatus and method include user equipment (UE) that first receives a downlink grant (DL-GRANT) which schedules downlink HARQ transmission in a time-frequency bundling window corresponding to an uplink subframe used for feeding back HARQ-ACK, obtains a DL downlink assignment index (DL DAI) in the DL-GRANT, and determines a mapping value of each DL DAI. Then, according to the mapping value of the corresponding DL DAI, the HARQ-ACK bit of each HARQ feedback unit is mapped to a corresponding bit of a feedback bit sequence. According to the method and apparatus provided by the present disclosure, useless HARQ-ACK bits may be effectively removed, and efficiency for feeding back HARQ-ACK may be increased. As such, a downlink peak rate of a UE is ensured.