PURPOSE: To provide a resin compsn. reactive for visible light which rapidly reacts with irradiation of visible semiconductor laser beam, and to provide a sheet type optical recording material in which an excellent image is formed.

CONSTITUTION: This resin compsn. reactive for visible light contains (a) p- vinylphenol polymer having ≥4000 weight average mol.wt., (b) cation reactive compd., (c) 2,4,6-tris(trichloromethyl)-1,3,5-triazine, (d) squarylium salt sensitizing dye having the max. absorption wavelength between 600nm and 700nm, and (e) aromatic compd. expressed by formula. In formula, R1, R2 are substd. or unsubstd. satd. or unsatd. hydrocarbon groups, and R3 is a substd. or unsubstd. aliphatic group or a substd. or unsubstd. aromatic group. The resin compsn. is used to form a photosensitive recording layer of a sheetlike optical recording material.