Poly(ethylene-co-vinyl acetates), EVA, with a different content (from 5 to 25 w%) of the vinyl acetate group (VA) in a macromolecular chain were blended with potato starch in the melt under pressure. Swelling of these blends in liquid water, in water vapor, and biodegradation in a wet soil were determined. Swelling in water and water absorption increased with the content of VA group in copolymer macromolecules and starch in polymer blends. Addition of starch to EVA copolymers promoted biodegradability of the polymer blends that might be used for production of biodegradable materials.