A method and a user equipment (UE) for transmitting an uplink (UL) signal in a wireless communication system supporting carrier aggregation are discussed. The UE is configured with a plurality of cells. A first cell and a second cell operate in time division duplex (TDD) and have different TDD uplink-downlink (UL-DL) configurations. The method according to an embodiment includes determining a specific TDD UL-DL configuration having a smallest number of D subframes from among one or more TDD UL-DL configurations, each of the one or more TDD UL-DL configurations being configured as a D subframe in each D subframe of the first cell and the second cell, the D subframe indicating a downlink (DL) subframe or a subframe comprising a downlink period, a guard period, and an uplink period; and transmitting a control signal in a UL subframe in response to at least one downlink signal.