Abstract: A mobile terminal apparatus and a radio communication method are provided which can efficiently transmit feedback control information through a physical uplink control channel. The radio communication method according to the present invention uses a plurality of ACK/NACK control bits as data signals, adds cyclic shifts to a plurality of reference signal blocks of a plurality of time blocks in a physical uplink control channel format comprised of a plurality of time blocks, multiplies the plurality of reference signal blocks by orthogonal codes and transmits a control channel signal including reference signals by which orthogonal codes are multiplied to a radio base station apparatus through a physical uplink control channel.