A radio transmission rate determining part (21) of a radio base station (2), when receiving transmission data transmitted from a base station control apparatus (1), determines a radio transmission rate in accordance with transmission data size and produces rate information. A transmission power changing part (22) decides the change amount of transmission power from the transmission data size received by the radio transmission rate determining part (21) and from an error correction gain difference determined in accordance with the transmission data size. A transmission frame producing part (23) encodes the transmission data into a transmission frame. A transmission part (249 transmits the transmission frame and rate information in accordance with the transmission power decided by the transmission power changing part (22).