A base station apparatus which conducts a packet communication with a wireless communication terminal includes: a retransmission request detection unit which detects a retransmission request from the wireless communication terminal; a bandwidth assignment unit which assigns a communication bandwidth applied to the packet communication; a modulation class calculation portion, based on both bandwidth information regarding the bandwidth assigned by the bandwidth assignment unit and a data amount of packets corresponding to the retransmission request, calculates a modulation class applied to a retransmission in order to adjust a number of retransmitted packets to be the same as a number of previously transmitted packets; a modulation class determination unit which determines whether or not the modulation class is lower than a modulation class applied to a previous packet transmission; and a retransmission unit which retransmits packets corresponding to the retransmission request based on the determination result regarding the modulation class.