Abstract: In a method of protecting a motor-driven power steering system from overheat, it is possible to prevent a set temperature value from being largely increased by the peripheral circuits of the electronic control unit and improve safety of the motor-driven power steering system by controlling steering current on the basis of the accurate temperature without the effect by the peripheral circuits, by determining when a temperature value measured by a temperature sensor of an electronic control unit is measured high by the peripheral circuits of the electronic control unit and making the set temperature value close to a previous-set temperature value.