To alleviate processing load of a communication apparatus (mobile station) for data transmission using the shared channels. A radio communication apparatus for receiving data via the shared channels, comprises a receiving unit for intermittent reception to determine whether the data received via the shared channels is transmitted to its own station or not in the first operational mode and a transmitting unit for intermittent transmission of information which influences the transmission format of the data a predetermined time before the intermittent reception timing of the receiving unit in the first mode.