A backlight unit of an LCD device includes a first light source unit including a plurality of red, green and blue LEDs and a second light source unit including a plurality of white LEDs, the white LED provided between each of the first light source unit. A control unit divides the plurality of first and second light source units into a plurality of blocks and outputs control signals to the first and second light source units by detecting the luminance of inputted video signals. The backlight unit includes a first light source driving unit for driving the first light source and a second light source driving unit for driving the second light source by corresponding block to the first light source unit.