PROBLEM TO BE SOLVED: To provide a composition having high gloss, excellent in heat resistance and shock resistance, having strong weld strength and capable of lowering a mold temperature during injection molding, and to provide an injection molded article.SOLUTION: A polylactic acid resin composition contains: (A) a polylactic acid resin (A component) which contains (A-1) poly-L lactic acid mainly containing an L-lactic acid unit (A-1 component) and (A-2) poly-D lactic acid mainly containing a D-lactic unit (A-2 component) and has a weight ratio of the A-1 component and the A-2 component in a range of 10:90 to 90:10, in which the poly-L lactic acid resin (A-1 component) contains the L-lactic acid unit at 90 mol% or more and the poly-D lactic acid resin (A-2 component) contains the D-lactic acid unit at 90 mol% of 100 pts.wt.; (B) an amide based organic nuclear agent (B component) of 0.01 to 3 pts.wt.; and (C) an impact modifier (C component) of 1 to 20 pts.wt.
