A driving circuit for an LCD system is provided. The LCD system includes a common electrode, a display electrode, and a capacitor. An AC voltage output terminal of the driving circuit is coupled to the common electrode via the capacitor. The display electrode and a charging/discharging unit in the driving circuit are respectively coupled to the AC voltage output terminal through a switch. According to requirements to change the electrical polarity of the common electrode, a control unit in the driving circuit turns on/off the two switches respectively so as to charge or discharge the AC voltage output terminal.