Abstract: A method for preparinq a lithographic printing plate comprising the steps of imagewise exposing, to light, a negative-working presensitized plate for use in making a lithographic printing plate which comprises a substrate provided thereon with a light-sensitive layer comprising an aromatic diazonium compound having at least one member selected from the group consisting of carboxyl groups, phenolic hydroxyl groups, sulfonic acid residues, sulfinic acid residues and phosphorus atom-containing oxyacid residues and developing the imagewise exposed presensitized plate with a developer which comprises an aqueous solution of an alkali metal or ammonium silicate having a ratio: [SiO.sub.2 ]/[M], wherein [SiO.sub.2 ] and [M] represent the molar concentrations of SiO.sub.2 and the alkali metal or ammonia in the developer respectively, ranging from 0.15 to 0.75 and an SiO.sub.2 content ranging from 1.0 to 4.