To provide a polylactic acid-based resin composition for an optical material, having excellent transparency and improved tensile characteristics; and to provide a molded article for the optical material, using the resin composition.

The polylactic acid-based resin composition for the optical material comprises 99.9-80 pts.wt. polylactic acid-based resin (a) and 0.1-20 pts.wt. polyhydroxyalkanoate copolymer (b) based on 100 pts.wt. total of the polylactic acid-based resin (a) and the polyhydroxyalkanoate copolymer (b).