A motor control system which can realize current detection with high accuracy by using an amplifier having an ordinary level of accuracy and can avoid deterioration of current detection accuracy even when emperature is changed. The motor control system comprises a switch circuit for supplying a driving current to a motor, a resistor for detecting the driving current, an amplification circuit for amplifying a potential difference across the resistor, an input section switch unit disposed in an input section of the amplification circuit and changing over the potential difference to be forward biased or reverse biased, an output section switch unit disposed in an output section of the amplification circuit and changing over an output voltage of the amplification circuit to be forward biased or reverse biased, and a CPU for averaging a voltage produced when the output voltage of the amplification circuit is forward biased, and a voltage produced when the output voltage of the amplification circuit is reverse biased.