To provide a development-free positive type heat sensitive lithographic printing original plate, with which no deterioration of printing performances such as non-staining properties are developed, grounds of an image forming layer developed through its abrasion with laser exposure are checked for scattering, resulting in rarely polluting the optical system of an exposing device.

This positive type heat sensitive lithographic printing original plate is produced by laminating an image forming layer, which is ink-acceptable and abraded with heat, and a water-soluble over-coating layer in the order named on a base plate having a hydrophilic surface.