A method for dividing a display area for local dimming of LCD is disclosed. The method includes determining an initial number of pixels per data analysis area and a total number of residual pixels, calculating a first residual pixel sum of a current data analysis area using the total number of residual pixels and a second residual pixel sum of a previous data analysis area, determining whether to assign a residual pixel to the current data analysis area using the first residual pixel sum and the total number of data analysis areas, calculating a second residual sum of the current data analysis area whether to assign a residual pixel, and repeating the calculation above until the data analysis area index is a last data analysis area index.