A backlight unit is disclosed which improves picture quality by preventing a bright line or a dark line from being visible in the center of the display area. The backlight unit includes a plurality of U-shaped lamps arranged in two columns, wherein curved portions of the two opposite U-shaped lamps are symmetrically positioned in the center of a display area. Each of the curved portions of the U-shaped lamps has a non-luminous part so that light is not emitted by the curved portions of the U-shaped lamps. Optical sheets are provided above the U-shaped lamps, and a reflective sheet is provided below the U-shaped lamps.