The invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting control information. The wireless communication system may support carrier aggregation (CA). A method for transmitting control information to a base station by a terminal in a wireless communication system according to one aspect of the present invention comprises the steps of: receiving at least one of either a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH) from said base station via at least one serving cell provided on the terminal; and transmitting, to said base station, control information on the reception of said PDCCH or on the reception of said PDSCH indicated by the PDCCH. Said at least one serving cell may use a frequency division duplex (FDD) frame structure or a time division duplex (TDD) frame structure. Said control information may be transmitted using a control information feedback timing of a first serving cell determined in accordance with a preset criterion from said at least one serving cell.