A power-window jamming preventing apparatus, includes a current sensing circuit, which senses a motor current flowing through a motor; a current limiting circuit, which increases and decreases the motor current based on a current-limitation control signal outputted from the current sensing circuit when an amount of increase of the motor current exceeds a predetermined vale; and a jamming determining circuit, which determines a jamming of a foreign matter in the window glass, and a potential difference generating circuit, which monitors a power source voltage supplied to the current sensing circuit and the power window motor, and which clamps a third reference voltage so as to drop a constant voltage from the third reference when the power source is low such that a potential difference between the second reference voltage and the third reference voltage is kept greater than a predetermined voltage.