In a mobile communication system in an embodiment, when a handover of a mobile station which is a target of coordinated communications among multiple wireless base stations is detected, at least a part of setting procedure for the coordinated communications (CoMP setting procedure) is executed before completion of the handover. Hence, the coordinated transmission for the mobile station can be resumed earlier after the handover, and any reduction in the communication quality or throughput caused by the resume of the coordinated communication after the handover of the mobile station can be prevented.