PURPOSE: To obtain the planographic printing plate for which a diffusion transfer processing liquid preferable in handling and management is used by subjecting a photosensitive material having at least silver halide emulsion layers and physical development nucleus layers on a base to diffusion processing in the presence of specific compds.

CONSTITUTION: In the plate making method for the planographic printing plate which utilizes the transferred silver by a silver complex salt diffusion transfer method as an ink accepting part; the printing plate is obtd. by subjecting the photosensitive material having at least the silver halide emulsion layers and the physical development nucleus layers on the base to the diffusion transfer processing in the presence of at least one kind of the compds. expressed by formula I and the compds. expressed by formula II. In the formula I, Z denotes the atom group necessary for perfecting 5- or 6-heretocycles together with N and C. In the formula I, R denotes a hydrogen atom, alkyl group, etc. In the formula II, R1 and R2 may be the same or different and may form a ring by bonding. R3 denotes an alkylene group where other bivalent groups may exist.