A wireless communication system to which carrier aggregation is applied performs effective traffic adaptation. In a terminal device which communicates with a base station device using two serving cells including one primary cell and one secondary cell, in a case that a UL-DL configuration for the primary cell is different from a first downlink reference UL-DL configuration for the secondary cell and the serving cell is the secondary cell, a second downlink reference UL-DL configuration for the serving cell is set on the basis of a pair which is formed by the UL-DL configuration for the primary cell and the first downlink reference UL-DL configuration for the serving cell.