A polymerizable composition comprising an ethylenic monomer, a photopolymerization initiator and a specific benzotriazole compound or sulfone compound, and a method for producing a lithographic printing plate comprising a step of exposing a light-sensitive layer containing the above-described polymerizable composition on a support with laser light having a wavelength of 450 nm or shorter and a step of treating the exposed light-sensitive layer with a developing solution having a pH of 13.0 or less.