In a radio communication system that simultaneously provides communication service using a plurality of discontinuous frequency bands, a multi-band radio communication method according to the present invention is a method in which a base station constituting the system allocates a band to a mobile station that requests a communication starting. For example, a specific receiving unit within the base station extracts control information concerning a channel state in each of the frequency bands, and recognizes a frequency band in which the mobile station can receive information, from a result of the extraction. A channel controller 9 determines, starting from a high frequency band, whether a new traffic responding to the communication starting request can be allocated in each frequency band.