A mobile communication method, in which radio base stations transmit common control signals to all of their covering areas, includes a first radio base station determining a reception power level of a common control signal transmitted by a surrounding radio base station; the first radio base station adjusting, based on the determined reception power level of the common control signal, the transmission power level of the common control signal; and (C) the first radio base station and surrounding radio base station, when having detected that no mobile stations are existent under charge of those radio base stations, reducing the transmission power levels of the common control signals.