A method for transmitting hybrid automatic repeat request-acknowledgement, HARQ-ACK, information performed by a user equipment, UE, comprising determining (101, 301) a channel for transmitting a HARQ-ACK; determining, according to HARQ-ACK timing of each carrier, the number of downlink subframes corresponding to a current subframe for each carrier; determining HARQ-ACK feedback bits based on the number of downlink subframes for each carrier; and sending (103, 304) the HARQ-ACK feedback bits on the channel in the current subframe; wherein the HARQ-ACK timing of each carrier comprises: when at least one carrier uses a frequency division duplex, FDD, manner and at least one carrier uses a time division duplex, TDD, manner in carriers for carrier aggregation for the UE, and if, in subframe n, a physical downlink shared channel, PDSCH, is detected in the carrier that uses the TDD manner or a physical downlink control channel, PDCCH, indicating semi-persistent scheduling release is detected in the carrier that uses the TDD manner, the HARQ-ACK corresponding to the PDSCH or the PDCCH shall be fed back in subframe n+4; wherein the channel is a PUCCH, and the determining the HARQ-ACK feedback bit comprises: determining the HARQ-ACK feedback bit based on the number of carriers configured for the UE, a transmission mode of each carrier, and the number of downlink subframes corresponding to the current subframe for each carrier, wherein the number of the HARQ-ACK bits satisfies following formula: O ACK = N subframe ·( C+C 2), where O ACK is the number of bits of the HARQ-ACK, N subframe is the number of downlink subframes corresponding to the current subframe, C is the number of configured carriers, and C 2 is the number of carriers where a configured transmission mode may support dual-codeword transmission. determining (101, 301) a channel for transmitting a HARQ-ACK; determining, according to HARQ-ACK timing of each carrier, the number of downlink subframes corresponding to a current subframe for each carrier; determining HARQ-ACK feedback bits based on the number of downlink subframes for each carrier; and sending (103, 304) the HARQ-ACK feedback bits on the channel in the current subframe; wherein the HARQ-ACK timing of each carrier comprises: when at least one carrier uses a frequency division duplex, FDD, manner and at least one carrier uses a time division duplex, TDD, manner in carriers for carrier aggregation for the UE, and if, in subframe n, a physical downlink shared channel, PDSCH, is detected in the carrier that uses the TDD manner or a physical downlink control channel, PDCCH, indicating semi-persistent scheduling release is detected in the carrier that uses the TDD manner, the HARQ-ACK corresponding to the PDSCH or the PDCCH shall be fed back in subframe n+4; wherein the channel is a PUCCH, and the determining the HARQ-ACK feedback bit comprises: determining the HARQ-ACK feedback bit based on the number of carriers configured for the UE, a transmission mode of each carrier, and the number of downlink subframes corresponding to the current subframe for each carrier, wherein the number of the HARQ-ACK bits satisfies following formula: O ACK = N subframe ·( C+C 2), where O ACK is the number of bits of the HARQ-ACK, N subframe is the number of downlink subframes corresponding to the current subframe, C is the number of configured carriers, and C 2 is the number of carriers where a configured transmission mode may support dual-codeword transmission. determining the HARQ-ACK feedback bit based on the number of carriers configured for the UE, a transmission mode of each carrier, and the number of downlink subframes corresponding to the current subframe for each carrier, wherein the number of the HARQ-ACK bits satisfies following formula: O ACK = N subframe ·( C+C 2), where O ACK is the number of bits of the HARQ-ACK, N subframe is the number of downlink subframes corresponding to the current subframe, C is the number of configured carriers, and C 2 is the number of carriers where a configured transmission mode may support dual-codeword transmission.