A piston ring for an engine may include a piston ring body. The piston ring body may include a working surface, a lower surface, an upper surface, and an inner surface. An area of the working surface and/or the lower surface which is close to an outer circumferential lower edge of the piston ring body is not provided with a nitride layer, the outer circumferential lower edge is formed with a chamfer, the chamfer does not have a nitride layer, and an additional area of the piston ring has a nitride layer.