Disclosed are a backlight unit and a display apparatus using the same. The backlight unit includes a light guide plate, grooves disposed in the light guide plate, the grooves having at least one inclined surface, light source modules disposed within the grooves, and stoppers disposed between the light source modules and the light guide plate, wherein a cross-sectional area of the grooves is larger than that of the stoppers. The stoppers contact at least one of the side surfaces of the grooves, the bottom surfaces of the grooves and the light source modules.