Provided is a system for controlling temperature of a gear box for a wind power generator gear box. The system for controlling a temperature according to an exemplary embodiment of the present invention includes: a temperature sensor configured to measure a temperature of the gear box; a temperature adjustment unit configured to adjust the temperature of the gear box in accordance with the temperature of the gear box which is measured by the temperature sensor; a pitch adjustment unit configured to adjust a pitch angle of the blade; and a control unit configured to control the pitch adjustment unit so that the blade is rotated at a rotating speed for heating when the measured temperature of the gear box is lower than a range of a normal operating temperature of the gear box.