The wireless communication system includes a base station (10) and a mobile station that communicates with the base station (10). The base station (10) includes a sending unit (17). The sending unit (17) sends, to the mobile station, a first signal that indicates, as a notification, reduction of the number of candidates for channels each of which includes control information addressed to the mobile station. The mobile station includes a receiving unit and a number-of-candidates reducing unit. The receiving unit receives the first signal sent by the sending unit (17). The number-of-candidates reducing unit monitors one or a plurality of channels the number of which has been reduced, from the candidates, based on the first signal and acquires the control information from the one or the plurality of channels.