Transmission power of a plurality of uplink carrier components used for communication by a mobile station apparatus and a base station apparatus is effectively controlled. The mobile station apparatus communicates with the base station apparatus using plurality of downlink component carriers and a plurality of uplink component carriers. The mobile station apparatus sets a plurality of groups, and each of the groups is composed of at least one uplink component carrier. The mobile station apparatus receives multiple pieces of control information regarding each of the groups to the mobile station apparatus from the base station apparatus in a single downlink component carrier.