PURPOSE: To obtain the titled printing plate improved for stains without decrease of printing resistance, by a method wherein the aluminum plate is processed with electrolytic coarsening treatment, treated by etching within a specific range, anodized and thereafter, the negative type photosensitive layer is provided.

CONSTITUTION: The aluminum plate preferably processed with mechanical coarsening treatment and chemical etching treatment, is successively processed with coarsening treatment using alternating waveform current or the like in the electrolyte of nitric acid, and then processed with etching treatment by dissolving aluminum within a range of 0.1W0.5, preferably 0.15W0.35g/m2 by the acid or alkali aqueous solution of 0.5W40wt%. Thereafter, electric current is applied in the aqueous solution of sulfuric acid of 1W80wt% or like, and the anodic oxidation film is formed on the surface of aluminum plate. The obtained sheet printing plate substrate is coated with the sensitizing solution containing diazo resin and the negative type photosensitive layer is provided. Then, it is photoengraved and the aimed printing plate is obtained.