A film easily soluble in cold water includes a water-soluble copolymer composed of 2 to 40 mol % of an allyl ester moiety, 97.5 to 50 mol % of a vinyl ester moiety and 0.5 to 10 mol % of at least one member selected from the group consisting of unsaturated monocarboxylic acid, unsaturated dicarboxylic acid and anhydrides thereof, and the copolymer has a degree of saponification of not less than 65 mol %. The film is easily soluble in cold water and such solubility in cold water is not lowered even if the film comes into contact with either alkaline or acidic materials and it can suitably used as wrapping material for packages which are directly thrown into water together with packed materials. The copolymer may be used of such an allyl ester, vinyl ester and further one of unsaturated carboxylic acids.