A mobile communication system of an embodiment is a system in which a plurality of radio base stations receive an uplink signal transmitted from a radio terminal coordinated with one another. Each of the plurality of radio base stations comprises: an acquisition unit that acquires a path loss between the radio terminal and the radio base station; and an interface that notifies the path loss acquired by the acquisition unit to another radio base station. At least one the radio base station of the plurality of radio base stations includes a notification unit that notifies the radio terminal of the path loss used in the transmission power control of the uplink signal, in accordance with the path losses between each of the plurality of radio base stations and the radio terminal.