A liquid crystal display device includes a display unit, a back light assembly having a light source, a light guiding plate, a light focusing portion, and a mold frame divided into a first frame and a second frame. The mold frame receives the display unit and the back light assembly. The first frame receives the light guiding plate and the light focusing portion and the second frame receives the light source. A reflection sheet is integrally formed at an inner surface of the second frame so as to perform the function of a lamp reflector. Accordingly, a lamp cover is not required so that the number of parts and the manufacturing cost are reduced. A lamp can be exchanged by simply separating the second frame from the mold frame, so failure of the light source caused by friction with other elements is reduced when exchanging the lamp.