Abstract: A packing case molded from plastic materials comprises two side walls including two half-walls rotatably connected to each other by tenon/mortise joint and hinge elements, two end walls rotatably connected to the adjacent side walls by tenon/mortise joint and hinge elements, and two cover plates removeably intersecting with said connected walls, thereby to form a foldable container which can easily pack or unpack without need of any external means, and can be folded into a collapsed form that is easily recovered for further use.