PURPOSE: To provide a photosensitive sheet excellent as an ornamental or display material and further to provide a silver salt offset printing plate excellent in printing durability and picture reproducibility in the monosheet-type diffusion- transfer silver salt photosensitive sheet with an anodized aluminum plate as the substrate.

CONSTITUTION: A physical development nucleus and a silver halide photosensitive layer are formed on an anodized aluminum substrate to constitute a diffusion-transfer silver salt photosensitive sheet. The anodic oxide film of the photosensitive sheet is formed by using an electrolyte contg. sulfuric acid to anodize the substrate by AC electrolysis, allowing the substrate to react with an aq. metallic ion-contg. soln. to form a physical development nucleus and further providing a silver halide photo-sensitive layer thereon, and the physical development nucleus is formed in the pore of the anodic oxide film.