An array substrate and a liquid crystal display device. The array substrate comprises array structures (12) and pixel electrodes (13) which are both formed on a first substrate (11). At least part of pixel regions corresponding to the pixel electrodes (13) are provided with optical diffuse reflection structures (14). The pixel regions include pixel regions corresponding to different color pixels. The optical diffuse reflection structures (14) are set as follows: the light reflectivity of the optical diffuse reflection structure (14) of the pixel region corresponding to the color pixel which has the longest optical wavelength is less than that of the optical diffuse reflection structure (14) of the pixel regions corresponding to other color pixels.
