A resin composition comprising a polylactic acid-based resin (A) and methacrylic resins (B), wherein the methacrylic resins having at least (a) a difference of 10.degree. C. or more in glass transition temperature or (b) a difference of 3% or more in syndiotacticity; it is preferred that at least one of the methacrylic resins (B) is a methacrylic resin having a weight average molecular weight of 50,000 to 450,000, a glass transition temperature of 110.degree. C. or higher and a syndiotacticity of 40% or more, and that the resin composition further contains a multilayer structure polymer formed as particles each consisting of a core layer and one or more shell layers covering it (C) A molded article made of said resin composition.