A wireless communication system includes a wireless base station, a mobile station configured to communicate with the wireless base station, and a relay station configured to relay the communication between the wireless base station and the mobile station. When the number of the mobile stations communicating with the wireless base station is judged to have become smaller than or equal to a given number, a power controller in the relay station executes at least one of power control to cut off the power for relaying the communication, power control to perform intermittent operation, and power control to perform power-saving operation.