There is provided an infrared-sensitive lithographic printing plate capable of direct plate-making based on digital data from a computer or the like, and excellent in development latitude and scratch resistance, which is an infrared-sensitive lithographic printing plate comprising a support and a heat-sensitive layer, the heat-sensitive layer comprising (A) a copolymer having a specific monomer unit having a carboxyl group, (B) an alkali-soluble high molecular weight compound having a sulfonamide group, and (C) a light-heat conversion material.