Abstract: Disclosed is an improved structure for a paper shredder in a waste paper disposer formed of one piece design composed of a hanging portion, and a shredder body with a plurality of scrapping elements and guiding slots. The structure is divided in two parts, provided respectively at the front and rear sides of a cutter assembly. During operation of the paper shredder, the paper shreds are removed from the cutter assembly by the scrapping elements of the shredder body thereby preventing the paper scraps from sticking on the cutter surfaces. Paper scraps sticking on the cutter blades are removed by barrier tips on the upper ends of the guide slots. When the paper shredder is reversely revolved, the remaining paper shreds on the cutter are removed by the barrier tails formed at the bottom portion of the shredder and the guide slots.