The planographic printing plate precursor of the present invention
comprises a support, and a hydrophilic layer disposed on the support and
having a hydrophilic graft chain and a crosslinked structure formed by
hydrolyzing or polycondensing an alkoxide of an element selected from Si,
Ti, Zr and Al, wherein the hydrophilic layer comprises a photothermal
conversion agent (A) and a compound (B) capable of forming a hydrophobic
surface area by being heated or irradiated with radiation, and the
photothermal conversion compound (A) is not included in the compound (B).
This planographic printing plate precursor can be set, without being
developed, onto a printer after images are formed, so as to perform
printing. In addition, the precursor has remarkably improved printing
stain resistance and printing resistance.