A lighting device is provided and includes a light guide plate including a plurality of light incident surfaces and two light emitting surfaces, a plurality of edge frames, and at least one light source. Each of the edge frames includes a main body including an accommodating groove and an opening, first and second clamp members, and first and second fixing elements respectively located on first and second ends of the main body. The light emitting surfaces are clamped by the first and second clamp members of each edge frame. Each of the light incident surfaces is inserted in the main body of one of the edge frames through the opening and accommodated in the accommodating groove. The light source is located in the accommodating groove of one of the edge frames and adjacent to the corresponding light incident surface.