A color-fliterless liquid crystal display device includes a plurality of pixel units, each pixel unit includes a first sub-pixel and a second sub-pixel. The liquid crystal display device includes a plurality of light sources, each for emitting light having various wavelength ranges. A guide plate contains a first reflective surface and a second reflective surface for guiding light having various wavelength ranges toward the first and second sub-pixels. Accordingly, various gray levels shown by each pixel unit are combined by the two sub-pixels based on the light having various wavelength ranges