PURPOSE: To obtain a base for a planographic printing plate free from contamination of non-image parts or ground contamination while retaining durability to printing, by a method wherein an aluminum plate is sanded, is then subjected to anodic oxidation, and is treated in a specified solution.

CONSTITUTION: The aluminum plate used as a blank material of the base for the planographic printing plate is subjected to sanding, and then to anodic oxidation. The aluminum plate is then treated in a diluted aqueous solution of a salt of a divalent metal and phytic acid or a salt thereof at a temperature of 60W 100°C. The aluminum plate thus treated is washed with water to remove excess treating solution, is dried, and then a photosensitive layer is provided thereon by coating. A photosensitive composition for constituting the photosenstive layer preferably comprises o-quinonediazide compound. A photosensitive planographic printing plate thus manufactured has high adhesive strength between the aluminum plate as the base and the photosensitive layer provided thereon, has excellent durability to printing, and a printed matter obtained thereby is completely free from ground contamination.