An over-driving look-up table automatic setting apparatus for a liquid crystal display device includes: an input device that specifies a critical response condition for a liquid crystal display device; a sensor that detects an amount of light from the liquid crystal display device and that generates a signal corresponding to the amount of light; a response state detecting unit that measures the response state from the signal generated by the sensor; a controller that receives the response state for gray scale differences from each of a plurality of gray scale values to determine transient pixel data producing a response state that satisfies the critical response condition and that sets an over-driving look-up table by mapping the transient pixel data to corresponding gray scale difference values for each gray scale value; and a memory that stores the over-driving look-up table.