To provide an original plate for a planographic printing plate capable of stably foreming the planographic printing plate good in on-machine developability and having high sensitivity and high printing durability, and a printing method reducing treatment for forming an image forming layer and having high sensitivity and high printing durability.

The original plate for the planographic printing plate is constituted by providing an image forming layer, which contains thermoplastic polymer particles having a large number of whisker-like projections and a photothermal converting agent, on a support. The printing method has a process for forming the image forming layer 13 by electrically depositing the thermoplastic polymer particles on the hydrophilic support 11 by applying an electric field across the hydrophilic support arranged on the plate cylinder 1 of a printing press and a dispersion prepared by adding at least the thermoplastic polymer particles having a large number of whisker-like projections, the photothermal converting agent and a charge control agent in an electric insulating liquid, a process for imagewise exposing the image forming layer 13 and a process for performing printing after removing a non-image part by ink, water or rubbing.