The present invention is designed to realize signaling of DM-RS sequence parameters for improving the flexibility of allocation of DM-RS resources in a system having complex cell structures. According to the radio communication method of the present invention, in a radio communication system supporting a system band formed with a plurality of component carriers by carrier aggregation, a radio base station apparatus allocates uplink DM-RS sequences per mobile terminal apparatus and per component carrier, and reports DM-RS sequence allocation information, and a mobile terminal apparatus generates DM-RS sequences using the allocation information reported from the radio base station apparatus.