A film easily soluble in cold water comprises a water soluble copolymer composed of 3 to 30 mol% of an allyl ester, 96.5 to 65 mol% of a vinyl ester and 0.5 to 5 mol% of an unsaturated carboxylic acid and its anhydride and having a degree of saponification of not less than 70 mol%. The film is easily soluble in cold water and such solubility in cold water does not change even if it comes into contact with either alkaline or acidic materials and it can be suitably used as wapping material for package which are directly thrown into water together with packed materials.