BACK LIGHT UNIT AND LIQUID CRYSTAL DISPLAY USING THE SAME

A backlight unit and an LCD using the same are provided to prevent a light diffusion plate and an optical sheet from being cracked, and simplify manufacturing of the backlight unit. The backlight unit includes a plurality of lamps, a bottom cover(102) receiving the lamps and forming an open part, the light diffusion plate covering the open part of the bottom cover and diffusing light of the lamps, and the optical sheet which is layered on the light diffusion plate and at least one groove respectively is formed on there. The bottom cover includes the first guide(130a) guiding the light diffusion plate by being projected from an upper side of the bottom cover and the second guide(130b) guiding the optical sheet by being projected from the first guide to be inserted into the groove. An edge of the light diffusion plate is facially touched to a side of the first guide on the upper side of the bottom cover. The edge of the optical sheet is facially touched to the side of the second guide on the upper side of the first guide.