A method for controlling a clothes dryer is disclosed to precisely dry clothes on the basis of a load amount according to moisture contained in clothes in the clothes dry and a temperature change according to proceeding drying of clothes. The method includes: detecting a load amount detect signal corresponding to an amount of moisture contained in clothes in a drum; setting a heater exit temperature range of the clothes dryer to pre-set first and second temperature ranges on the basis of the load amount detect signal, and first drying clothes in the drum within the pre-set first temperature range; second-drying clothes in the drum within the pre-set second temperature range; and cooling clothes in the drum when the first and second-drying processes are completed.