Disclosed are an LCD device and a driving method thereof. The LCD device includes at least one source driving ICs configured to drive a plurality of data lines formed in a panel, a timing controller configured to generate a power control signal used to change a level of a driving voltage applied to the source driving ICs according to a pattern of an image output to the panel, and a driving voltage generator configured to generate a first driving voltage or a second driving voltage according to the power control signal to drive the source driving ICs. The first and second driving voltages have different levels.