Provided are an original printing plate for relief printing that solves both the problems of the prior-art negative film or its alternatives, and problems of mask pattern formation directly on the surface of the photosensitive resin layer by an ink composition, as well as a method for forming an relief printing plate using the same. Employing a photosensitive original printing plate for relief printing including a support substrate (A); a photosensitive resin layer (B) provided thereon and having a photosensitivity to light in a predetermined wavelength region; and an ink holding layer (C) provided thereon; wherein the layer (C) is capable of retaining a light-shielding ink, and capable of constituting a light-shielding pattern inside the layer (C), the light-shielding pattern being formed by applying the light-shielding ink to the (C) in accordance with the pattern; and wherein the (C) at the area to which the light-shielding ink is not applied is substantially transparent to the light in the predetermined wavelength region.