A display controlling method is provided. The display controlling method includes following steps. A plurality of display data of a frame is received. The display data is analyzed to obtain a plurality of grayscale distributions corresponding to the display regions. According to the grayscale distributions, a backlight controlling signal for adjusting a brightness of each of the light emitting groups is generated. According to the backlight controlling signal, a plurality of interferences corresponding to the display data is obtained. According to the interferences, grayscales of the display data are correspondingly adjusted. Therefore, the optical interference of each of the pixels from the light emitting groups not corresponding to the pixels can be eliminated.