A stepping motor driving system includes: a stepping motor that rotates at a predetermined angle according to a driving pulse signal, a vibration detector that detects vibration to output a vibration signal, and a stepping motor control unit that controls the driving pulse signal, which is applied to the stepping motor, to rotate the stepping motor at the predetermined angle. The driving pulse signal includes a start-up current which is required for rotating the stepping motor at a unit angle and a holding current which maintains a rotational angle of the stepping motor rotated by the start-up current. The stepping motor control unit changes the level of the holding current according to the vibration signal which is outputted from the vibration detector.