A method is provided for transmitting Acknowledgement/Negative Acknowledgement (ACK/NACK) information in a wireless communication system. A User Equipment (UE) configures a Physical Uplink Control Channel (PUCCH) format 3 for transmission of the ACK/NACK information. The UE transmits the ACK/NACK information for downlink transmission in a downlink subframe set including M downlink subframes in one uplink subframe, wherein M>1. A plurality of serving cells are configured for the UE and include one Primary Cell (PCell) and at least one Secondary Cell (SCell). The UE transmits the ACK/NACK information using a PUCCH format 1b when a first condition is met that comprises a condition in case where the ACK/NACK information corresponds to one Physical Downlink Shared Channel (PDSCH) without a corresponding Physical Downlink Control Channel (PDCCH) received only on the PCell in the downlink subframe set and the ACK/NACK information corresponds to an additional PDSCH indicated by detection of one corresponding PDCCH.