Provided are a method and apparatus for transmitting and receiving a signal of a user equipment in a time division duplex (TDD)-based carrier aggregation system. The method includes: receiving a downlink grant for at least one subframe of a secondary cell via a subframe of a primary cell; and receiving downlink data in the at least one subframe of the secondary cell on the basis of the downlink grant, wherein the primary cell and the secondary cell are set to different downlink (DL)-uplink (UL) configurations among DL-UL configurations indicating how a downlink subframe and an uplink subframe are configured in a radio frame, and wherein the downlink grant includes a downlink subframe index (DSI) indicating the at least one subframe of the secondary cell.