A light string includes a plurality of lights and a plurality of non-polarity capacitor corresponding to the lights; wherein, the lights are electrically connected in series and to be powered by an AC power supply; each of the non-polarity capacitor is connected in parallel to a corresponding one of the lights. When the light string is powered on, the non-polarity capacitor is charged and absorbs the surge current which may occur. Thus, the voltage dropped on each light rises slowly and the lights are safe. The non-polarity capacitor also performs power compensation and electrical connection.