disclosed is a method for controlling reverse transmission power in a cellular mobile communication system . a base station measures interference in a cell divided into a plurality of beamforming areas , determines an interference availability bit of a specific area where the measured interference is greater than or less than a threshold , and forms a beam so as to transmit the determined iab to a beamforming area including the specific area . a terminal receiving the formed beam receives the iab , and controls reverse transmission power according to the received iab .