A hydrophobic biodegradable material contains host material and foamer. The host material is a product by melting a mixture, which comprises polyol, polyvinyl alcohol containing water, and starch contained or not. Said polyvinyl alcohol is a hydrophobic polyvinyl alcohol. The host material in the hydrophobic biodegradable material of the present invention is a product by melting the swollen hydrophobic polyvinyl alcohol, polyol and starch that is chosen to be contained or not. The melt temperature of the obtained host material is 130-210, which is much lower than its decomposition temperature which is 240-420, so it may be in molten state, and in a true sense can be extrusion-granulated and foaming-molded. The resulting foamed articles, produced by the hydrophobic biodegradable material of the present invention, have good expansion ratio that is more than 45%, compressive strength which is not less than 35 Kpa, water resistance and biodegradability.