A driving circuit used in a liquid crystal display device is disclosed which includes a timing controller, a source driver and a low color scale driving circuit. The timing controller outputs a polarity inverting signal, a first digital signal, a second digital signal, a third digital signal and a fourth digital signal. The low color scale driving circuit generates a first analog signal, a second analog signal, a third analog signal and a fourth analog signal according to the digital signals outputted from the timing controller for driving a liquid crystal panel. Through the low color scale driving circuit, power consumption of the liquid crystal display device reduces when operating in the condition of low color scale.