A mobile station apparatus which communicates with a base station apparatus using a plurality of component carriers, the mobile station apparatus characterized by comprising: a reception unit configured to receive, from the base station apparatus, information which is used to assign a physical uplink shared channel resource; and a transmission unit configured to transmit, to the base station apparatus, uplink control information using a single physical uplink control channelresource in case that the physical uplink shared channel resource is not assigned and a plurality of uplink control channel resources is assigned, wherein the transmission unit is further configured to transmit, to the base station apparatus, the uplink control information using the physical uplink shared channel resource assigned on a first uplink component carrier in case that the physical uplink shared channel resource is assigned on the first uplink component carrier, the first uplink component carrier being used for transmitting the uplink control information using the single physical uplink control channel resource in case that the physical uplink shared channel resource is not assigned and the plurality of physical uplink control channel resources is assigned, and the transmission unit is further configured to transmit, to the base station apparatus, the uplink control information using the physical uplink shared channel resource assigned on a second physical uplink component carrier in case that the physical uplink shared channel resource is not assigned on the first uplink component carrier but the physical uplink shared channel resource is assigned on the second uplink component carrier. a reception unit configured to receive, from the base station apparatus, information which is used to assign a physical uplink shared channel resource; and a transmission unit configured to transmit, to the base station apparatus, uplink control information using a single physical uplink control channelresource in case that the physical uplink shared channel resource is not assigned and a plurality of uplink control channel resources is assigned, wherein the transmission unit is further configured to transmit, to the base station apparatus, the uplink control information using the physical uplink shared channel resource assigned on a first uplink component carrier in case that the physical uplink shared channel resource is assigned on the first uplink component carrier, the first uplink component carrier being used for transmitting the uplink control information using the single physical uplink control channel resource in case that the physical uplink shared channel resource is not assigned and the plurality of physical uplink control channel resources is assigned, and the transmission unit is further configured to transmit, to the base station apparatus, the uplink control information using the physical uplink shared channel resource assigned on a second physical uplink component carrier in case that the physical uplink shared channel resource is not assigned on the first uplink component carrier but the physical uplink shared channel resource is assigned on the second uplink component carrier.