PURPOSE: To obtain a photo-setting resin composition easily polymerizable and curable by the irradiation of light to form a cured coating film having little gas emission and exerting little influence on the adherend coated with the composition by compounding a photo-setting resin component with a specific photopolymerization initiator.

CONSTITUTION: The composition is produced by compounding (A) a photo-setting resin component with (B) a photopolymerization initiator consisting of a compound containing a (meth)acryloyl group and obtained by reacting (i) an active hydrogen-containing compound capable of generating radicals by photo- irradiation (preferably 1-hydroxycyclohexyl phenyl ketone, etc.) with (ii) a (meth) acryloyl isocyanate of formula (R is H or CH3). The amount of the component B is preferably 0.5-20 pts.wt. based on 100 pts.wt. of the component A. The component A is e.g. unsaturated polyester and epoxy (meth)acrylate.