A wireless communication system capable of wireless communication by using multiple frequency bands at the same time, comprising: a mobile station including a baseband unit configured to synthesize a plurality of signals of the multiple frequency bands; an uplink transmitting unit configured to transmit allowable power difference between frequency bands and mode information indicating an object of power limitation in transmission power control of the mobile station to a base station, the object of power limitation being a transmission power value when the baseband unit is configured to synthesize the signals in a time domain, the object of power limitation being a power spectral density of the transmission power value when the baseband unit is configured to synthesize the signals in a frequency domain; and a transmission-power control unit configured to control transmission power on the basis of a transmission power control command received from the base station, and the base station including a generating unit configured to generate a transmission power control command on the basis of the allowable power difference between frequency bands and the mode information; and a downlink transmitting unit configured to transmit the transmission power control command to the mobile station. a mobile station including a baseband unit configured to synthesize a plurality of signals of the multiple frequency bands; an uplink transmitting unit configured to transmit allowable power difference between frequency bands and mode information indicating an object of power limitation in transmission power control of the mobile station to a base station, the object of power limitation being a transmission power value when the baseband unit is configured to synthesize the signals in a time domain, the object of power limitation being a power spectral density of the transmission power value when the baseband unit is configured to synthesize the signals in a frequency domain; and a transmission-power control unit configured to control transmission power on the basis of a transmission power control command received from the base station, and a baseband unit configured to synthesize a plurality of signals of the multiple frequency bands; an uplink transmitting unit configured to transmit allowable power difference between frequency bands and mode information indicating an object of power limitation in transmission power control of the mobile station to a base station, the object of power limitation being a transmission power value when the baseband unit is configured to synthesize the signals in a time domain, the object of power limitation being a power spectral density of the transmission power value when the baseband unit is configured to synthesize the signals in a frequency domain; and a transmission-power control unit configured to control transmission power on the basis of a transmission power control command received from the base station, and the base station including a generating unit configured to generate a transmission power control command on the basis of the allowable power difference between frequency bands and the mode information; and a downlink transmitting unit configured to transmit the transmission power control command to the mobile station. a generating unit configured to generate a transmission power control command on the basis of the allowable power difference between frequency bands and the mode information; and a downlink transmitting unit configured to transmit the transmission power control command to the mobile station.