In a handover procedure between cells under different radio base stations (eNB), “RRC diversity” is implemented. A mobile communication method includes: a step A of transmitting, by a radio base station (eNB #1), “CoMP preparation” to a radio base station (eNB #10); a step B of transmitting, by the radio base station (eNB #10), setting information on a cell (#10) to the radio base station (eNB #1); a step C of conducting, by the radio base station (eNB #1), setting of the mobile station (UE) to perform CoMP transmission-reception; a step D of giving, by the mobile station (UE), the radio base station (eNB #1) notification that radio quality in the cell (#10) satisfies a predetermined condition; and a step E of instructing, by the radio base station (eNB #1), the radio base station (eNB #10) to start scheduling for the mobile station (UE).