<p>The present invention provides a method for producing curable resin which comprises reacting acrylic acid and/or methacrylic acid [which is hereinafter cited as (metha-) acrylic acid] with hydroxyl group-containing resin (I) obtained by reacting a five-member cyclic compound having an unsaturated conjugated double bond represented by the general formula (A) given below; GENERAL FORMULA (A): <IMAGE> (WHEREIN R is an organic residue having from 1 to 3 carbon atoms; m and n are integers and are in the relation of m+n=6) or the Diels-Alder addition product thereof (A) and a compound (B) having both reactive carbon-carbon double bond or bonds and towo or more hydroxyl groups within one and the same molecule thereof. In accordance with the present invention, curable coating composition comprising said curable resin can also be obtained. The resin of this invention can be very quickly cured by the exposure to heat or radiation.</p>
