The exemplary embodiment relates to a liquid crystal display device and a driving method thereof for reducing heat and electric consumption power of the data driving circuit. The exemplary embodiment includes: a liquid crystal display panel including a plurality of data lines crossing a plurality of gate lines and liquid crystal cells arranged in a matrix e; a timing controller generating a polarity control signal, deciding if a predetermined weak pattern data is input, and shifting a phase of the polarity control signal in a next frame period following a frame showing the weak pattern data when the weak pattern data is input; a data driving circuit reversing the polarity of the data voltage in response to the polarity control signal and supplying to the data lines; and a gate driving circuit supplying a gate pulse to the gate lines sequentially.