PURPOSE: To obtain a molding resin which is used for producing a fiber- reinforced molded article and gives a tough rigid preform excellent in ultraviolet transmission by incorporating a urethane acrylate, an α,β-ethylenically unsatd. monomer, and a peroxide initiator, each in a specified amt.

CONSTITUTION: This molding resin contains, based on the total resin wt., 25% or higher urethane acrylate formed by the reaction of at least one org. polyisocyanate, at least one α,β-ethylenically unatd. alcohol of the formula (wherein R2 is H or CH3; and R3 is alkylene or a caprolactam residue), and at least one polyhydric alcohol, 10% or higher α,β-ethylenically unsatd. monomer (e.g. styrene), and a catalytic amt. of a peroxide initiator {e.g. bis-[4-t- butylcyclohexyl]peroxydicarbonate}.