There is provided a multi-carrier communication method capable of preventing lowering of a throughput of another mobile device accompanying allocation of a sub-carrier for a new mobile station device. This multi-carrier communication method can acquire reception quality information for one of the sub-carriers already allocated in an MS (150a) from a BS (100a) and for one of the sub-carriers which can be allocated in the MS (150a) from the BS (100b). According to the reception quality information, a release sub-carrier is selected from the sub-carriers already allocated and a new-allocation sub-carrier is selected from the sub-carriers which can be allocated. The new-allocation sub-carrier has a frequency different from the already-allocated sub-carriers excluding the release sub-carrier. The BS (100a) is instructed to release the selected release sub-carrier and the BS (100b) is instructed to allocate the selected new-allocation sub-carrier in the MS (150a).