An overdrive accuracy adjustment device and method for use in a liquid crystal display panel is presented. According to a current grayscale value of a pixel in an awaiting to be displayed image and a previous grayscale value of the corresponding pixel in an already-displayed image, the corresponding overdrive grayscale value is found from a look-up table. In order to more efficiently use the limited storage capacity of the look-up table as well as improve the accuracy of the overdrive, in accordance with the physical characteristics of the liquid crystal display panel in particular (in particular to the grayscale values which often require the overdrive), the gap size between the current grayscale values and/or the gap size between the previous grayscale values may be adjusted in the look-up table, without having to increase the quantity of the overdrive grayscale values stored in the look-up table.