A method for transmitting uplink control information by a user equipment (UE) configured with a plurality of cells including a primary cell and a secondary cell in a wireless communication system is discussed. The method includes identifying, by the UE, a Hybrid Automatic Repeat reQuest-Acknowledgement (HARQ-ACK)(0) and a HARQ-ACK(1); and transmitting, by the UE, bits b(0)b(1) using a Physical Uplink Control Channel (PUCCH) resource among a plurality of PUCCH resources based on the HARQ-ACK(0) and the HARQ-ACK(1) to a base station (BS) for identifying the HARQ-ACK(0) and the HARQ-ACK(1). The b(0)b(1) and the PUCCH resource are given according to a relation including Table 1, where the HARQ-ACK(0) indicates an ACK/Negative ACK (ACK/NACK)/Discontinuous Transmission (DTX) response to a data block related to the primary cell, and the HARQ-ACK(1) indicates an ACK/NACK/DTX response to a data block related to the secondary cell.