A method and apparatus for transmitting ACK/NACK information in a wireless communication system are disclosed. In accordance with a method for transmitting ACK/NACK information, an ACK/NACK signal of downlink transmission in a downlink subframe set is transmitted in a single uplink subframe. In this case, if a first physical uplink control channel (PUCCH) format is established by a higher layer for a downlink receiver, and if one physical downlink shared channel (PDSCH) is transmitted in a downlink subframe set, the ACK/NACK information can be transmitted using a second PUCCH format on PUCCH resources established by a higher layer for the second PUCCH format.