The present invention relates to a wireless communication system. In particular, the present invention relates to a method and device for receiving control information regarding a coordinated multi-point (CoMP) set including a first cell and a second cell from a serving/transmitting point in a carrier aggregation (CA) based wireless communication system. The present invention includes: receiving information regarding the size of control information through higher-layer signaling; and monitoring a plurality of control channel candidates for each cell of the CoMP set through the first cell in the CoMP set and detecting the control information, wherein the size of information of the control information candidate for each cell is equally determined based on information regarding the size of control information.