The present invention relates to a power factor correction circuit for compensating distortion of an input current. According to the exemplary embodiment of the present invention, a turn-on interval length of a switch is controlled according to a voltage induced in a secondary winding wire of an inductor since the voltage induced in the secondary winding wire has information on an input voltage when the switch is turned on. The turn-on interval length of the switch is reduced when the input voltage is great and is increased when the input voltage is low. Therefore, distortion of the input current may be compensated by controlling the turn-on interval of the switch according to the voltage induced in the secondary winding wire without using an additional circuit for sensing the input voltage.