An emulsion of resin having a function of oxidation inhibition obtained by subjecting an antioxidant (A) having two or more alcoholic hydroxy groups, a polyol compounds (B) as an optical ingredient, a compound (C) having a carboxy group and an active-hydrogen group, and an organic polyisocyanate (D) to urethanation reaction in an organic solvent, neutralizing the resultant resin solution with a neutralizing agent (E), and then dispersing the solution in water. A resin having the function of oxidation inhibition is obtained from the emulsion.