Provided is an apparatus and method for controlling power in a mobile communication system. The apparatus includes a moving speed measuring unit for measuring a moving speed of the terminal, a Channel Quality Indicator (CQI) processing unit for requesting a base station to adjust a CQI report frequency when the moving speed measured by the moving speed measuring unit exceeds a threshold value, and determining a CQI report frequency based on information on the CQI report frequency received from the base station to report CQI, and a power controller for performing a power control in response to a power control signal created by the CQI reported from the base station.