To provide a photosensitive planographic printing plate material which is especially suited for exposure with a laser beam, having an emission wavelength in the range of 350-450 nm, and which has superior printing durability and excellent keeping quality, and to provide a plate-making method of the planographic printing plate material.

The photosensitive planographic printing plate material has on a support a photosensitive layer, including an alkali soluble polymer, a compound with an ethylenically unsaturated bond, and a hydrogen abstraction type photopolymerization initiator, and is characterized in that the alkali soluble polymer is a copolymer having a structural unit expressed by general formula (1).