A radio communication system in which a first radio communication apparatus selects a transmission format from among a plurality of transmission formats to transmit data according to a selected transmission format and a second radio communication apparatus receives the data transmitted from the first radio communication apparatus. The first radio communication apparatus including a control signal generator to generate a control signal for notifying the second radio communication apparatus of a change of a trend of a transmission format to be applied and a radio transmitter to transmit the generated control signal. The second radio communication apparatus including a receiving processor which switches a candidate of receiving formats used for finding a receiving format to obtain a normal reception result based on the control signal.