A negative image-recording material which can be imagewise-exposed by IR radiation from IR lasers and enables direct image formation from digital data of a computer or the like. The material, when used in a lithographic printing plate, ensures good hardenability in an image area, exhibits good printing durability, even if not heated for image-formation, and ensures a large number of good prints from the printing plate. The material includes (A) an IR absorber having an oxidation potential of at most 0.35 V (vs. SCE), (B) a thermal radical generator and (C) a radical-polymerizing compound. The material is imagewise-exposed to IR radiation for image formation. Preferably, the IR absorber (A) has, in a chromophoric group, an electron-donating substituent having a Hammett's &sgr;para value of at most −0.10, and the thermal radical generator (B) is an onium salt.