A method for transmitting positive-acknowledgement/negative-acknowledgement, ACK/NACK, in a time division duplex, TDD,-based wireless communication system in which M,M>2, downlink subframes are associated with an uplink subframe in each of a first serving cell and a second serving cell, the method comprising: receiving at least one data during M downlink subframes associated with an uplink subframe n in each of the first serving cell and the second serving cell; and transmitting an ACK/NACK response for the at least one data using one resource selected from four candidate resources in the uplink subframe n, wherein, during the M downlink subframes in the first serving cell, if a PDSCH, indicated by a detection of a first physical downlink control channel, PDCCH, with a downlink assignment index, DAI, value equal to 1 or a second PDCCH with a DAI value equal to 2 on the first serving cell, is received, or if a first semi-persistent scheduling, SPS, release PDCCH with a DAI value equal to 1 or a second SPS release PDCCH with a DAI value equal to 2 is received, a first candidate resource is determined based on a first control channel element, CCE, used for transmission of the first PDCCH or the first SPS release PDCCH, and a second candidate resource is determined based on a first CCE used for transmission of the second PDCCH or the second SPS release PDCCH, wherein, during the M downlink subframes in the second serving cell, if a PDSCH, indicated by a detection of a third PDCCH with a DAI value equal to 1 or a fourth PDCCH with a DAI value equal to 2 on the first serving cell, is received, a third candidate resource is determined based on a first CCE used for transmission of the third PDCCH, and a fourth candidate resource is determined based on a first CCE used for transmission of the fourth PDCCH, and wherein the one resource is selected from the four candidate resources according to ACK/NACK states for the at least one data received during the M downlink sub frames. receiving at least one data during M downlink subframes associated with an uplink subframe n in each of the first serving cell and the second serving cell; and transmitting an ACK/NACK response for the at least one data using one resource selected from four candidate resources in the uplink subframe n, wherein, during the M downlink subframes in the first serving cell, if a PDSCH, indicated by a detection of a first physical downlink control channel, PDCCH, with a downlink assignment index, DAI, value equal to 1 or a second PDCCH with a DAI value equal to 2 on the first serving cell, is received, or if a first semi-persistent scheduling, SPS, release PDCCH with a DAI value equal to 1 or a second SPS release PDCCH with a DAI value equal to 2 is received, a first candidate resource is determined based on a first control channel element, CCE, used for transmission of the first PDCCH or the first SPS release PDCCH, and a second candidate resource is determined based on a first CCE used for transmission of the second PDCCH or the second SPS release PDCCH, wherein, during the M downlink subframes in the second serving cell, if a PDSCH, indicated by a detection of a third PDCCH with a DAI value equal to 1 or a fourth PDCCH with a DAI value equal to 2 on the first serving cell, is received, a third candidate resource is determined based on a first CCE used for transmission of the third PDCCH, and a fourth candidate resource is determined based on a first CCE used for transmission of the fourth PDCCH, and wherein the one resource is selected from the four candidate resources according to ACK/NACK states for the at least one data received during the M downlink sub frames.