Disclosed is a resin composition excellent in molding processability which comprises a plant-derived biodegradable plastic produced by actively fixing carbon dioxide present in the earth. A resin composition excellent in molding processability, comprising (A) a biodegradable (3-hydroxyalkanoate) copolymer having a recurring unit represented by the formula (1): [—CHR—CH2—CO—O—] (wherein R represents an alkyl group represented by the formula CnH2n+1 and n is an integer of 1 to 15) and 0.1 to 100 parts by weight, based on 100 parts by weight of (A) the biodegradable (3-hydroxyalkanoate) copolymer, of (B) an acrylic modifier having a weight average molecular weight (Mw) of 500,000 to 10,000,000.