The dry film of vinyl chloride vinylidene chloride copolymer latex has some excellent pro perties, such as low permeability to water vapor, good chemical resistance, good waterproof property and high gloss. However, its shortcoming is easy to age and become yellow in the irradiation of ultraviolet rays. Adding antiaging agent into the emulsion coating is an effective way to protect its film againt aging. The paper deals with the influence of different kinds and amount of antiaging agent on the ageing resistance of the coating.