Disclosed is a resin composition excellent in impact resistance, tensile properties and processability such as draw down property, which is produced by using a plant-derived biodegradable polymer produced by actively fixing carbon dioxide present in the earth. A resin composition comprising (A) a specific biodegradable (3-hydroxyalkanoate) copolymer, (B) a graft copolymer and (C) an acrylic processing modifier, the graft copolymer (B) and the acrylic processing modifier (C) being contained in the composition in amounts of 0.1 to 100 parts by weight and 0.1 to 30 parts by weight, respectively, based on 100 parts by weight of the biodegradable (3-hydroxyalkanoate) copolymer (A).