To provide an original film for a heat mode type lithographic printing plate which is suitable for a scan type image exposure system plate making by laser beams and excellent in a discriminating property between an image area and a non-image area while the original film for the heat mode type lithographic printing plate wherein developing treatment is not required, plate can be made by a simple operation, the plate making can be executed by installing the original film directly to a printing machine, it is excellent in print wear and a print stain on the print surface is little, is provided.

An original film for lithographic printing has a surface hydrophilic and photocatalytic layer supporting fine pieces of photo-thermal convertion substance on a substrate wherein a lipophilic surface is provided or a lipophilic layer is installed. The original film for lithographic printing has a photocatalytic metallic compound layer supporting, on a surface, metal fine pieces procipitated by optically reducing metal salts of metallic elements of which ionization tendency is of a lower order (noble) than a hydrogen element by irradiating especially active light.