A communication system comprises a radio transmission apparatus for retransmitting data and a radio reception apparatus for receiving the retransmitted data. The radio transmission apparatus is configured to add a sequential number, first information and second information to each of a plurality of divided data which is generated by dividing the data to be retransmitted, and to transmit the plurality of divided data including the sequential number, the first information and the second information to the radio reception apparatus. The sequential number identifies the data to be retransmitted, the first information indicates the position of each of the plurality of divided data in the data to be retransmitted, and the second information indicates whether each of the plurality of the divided data is last data in the plurality of the divided data.