A back light assembly having an LED(light emitting diode) is provided to improve the light uniformity and the brightness by arranging white LEDs and color LEDs in a 'Y' shape to prevent a hot spot from being generated in a boundary between color LEDs. A light guide plate(100) includes protruding portions(110) formed on a side surface and recessed portions(120) formed between the protruding portions. The light guide plate guides a laterally provided light in an upward direction. A plurality of color LEDs are received in the recessed portions to provide a color light to the light guide plate. White LEDs are received in the protruding portions alternately with respect to the color LEDs to provide a white light to the light guide plate. The color LEDs and the white LEDs are arranged in a 'Y' shape.