An apparatus and method for driving a liquid crystal display device, which can selectively provide a wide viewing angle and a narrow viewing angle and improve the narrow viewing angle characteristics. The driving apparatus includes a liquid crystal panel having quad type unit pixels each including red, green and blue (RGB) sub-pixels and an electrical controlled birefringence (ECB) sub-pixel, a data driver for driving data lines of the liquid crystal panel, a gate driver for driving gate lines of the liquid crystal panel, and a timing controller for generating ECB data based on externally inputted RGB video data such that each of the unit pixels maintains a brightness of a constant level to form a narrow viewing angle, arranging the generated ECB data together with the video data and supplying the arranged data to the data driver.