Discussed are an apparatus and method for driving a liquid crystal display device, which can improve picture quality by changing a driving mode displaying images according to setting information from a user or to an image characteristic. An apparatus for driving a liquid crystal display device includes a liquid crystal panel including a plurality of pixel regions to display images, and a liquid crystal panel driving controller for performing either a black data addressing method for time-division driving the liquid crystal panel or a gate pulse modulation method for converting a level of a gate-on voltage supplied to the liquid crystal panel, according to setting information from a user or a moving image or still image characteristic of a currently displayed image.