An LCD backlight apparatus includes a light guide plate placed under an LCD panel of the LCD to guide light to the LCD panel. The light guide plate has an even upper surface and a scattering pattern formed in a bottom surface. A plurality of monochromatic light sources are placed in line at a side of the light guide plate to radiate light along the plane direction of the light guide plate between the upper and bottom surfaces of the light guide plate. The light sources are adapted to radiate light beams at a predetermined beam angle so that the light beams reach the scattering pattern only after having propagated a predetermined reference length necessary for forming white light when mixed together. The LCD backlight apparatus can reduce the Bezel width without increasing the thickness of the LCD.