In a mobile communication system in which a modulation and coding scheme is selected in accordance with reception quality information in which a terminal periodically reports to a base station, a method for causing a terminal located near the boundary of a cell to reduce its uplink transmit power by considering intercell interference and without incurring an increase in error rate. The method includes the steps of: a first base station detecting an interference level and terminal identification information identifying an interfering terminal, and transmitting interference information to all neighboring base stations; a second base station unit, as the serving base station of the terminal, receiving the interference information and transmitting control information to the terminal; and the terminal receiving the control information, reducing transmit power in accordance with the interference level, and adjusting reception quality information in such a direction so as to reduce quality.