A synchronous motor control system includes a motor including a stator having a plurality of sets of stator teeth and phase coils, a rotor having a plurality of rotor teeth disposed opposite the stator teeth and a stopper for restricting the rotation angle of the rotor relative to the stator and a control unit for sequentially controlling electric supply to the phase coils to rotate the rotor to a prescribed rotation position. The motor is controlled by the control unit to operate through the following steps of supplying current to a specific group of the phase coils, sequentially supplying current to the phase coils to rotate the rotor in one direction at a speed not to step out of synchronization to rotate the rotor until it is stopped by the means for restricting, and sequentially supplying current to the phase coils to rotate the rotor in the other direction at a speed not to step out of synchronization until the number of times of current supply becomes a prescribed number.