3-Methacryloyloxystyryl-2-naphthyl ketone containing a photosensitive alpha,beta -unsaturated ketone moiety was synthesized and polymerized in methyl ethyl ketone using benzoyl peroxide as the initiator. The thermally stable polymer was characterized by means of UV, and NMR spectroscopy. The molecular weight data as,obtained from gel permeation chromatography suggests a high tendency for chain termination by disproportionation. The. photosensitivity of the polymer in the presence and absence of photosensitizers and the effect of solvent on the rate of photocrosslinking (see Figure) was also investigated.