A method and an apparatus for controlling a compressor are provided. The method includes measuring a vehicle speed, an engine speed, a position value of an accelerator pedal, and an external air temperature and comparing the vehicle speed with a predetermined speed. A basic operation rate of the compressor is then determined based on the engine speed and the position value of the accelerator pedal when the vehicle speed is equal to or less than the predetermined speed. A final operation rate of the compressor is determined based on the external air temperature and the determined basic operation rate and the compressor is operated based on the determined final operation rate.