A polylactic acid resin composition obtained by adding a carboxylic ester or carboxamide having a polar group in each molecule to a polylactic acid resin having a (meth)acrylic ester compound caused to react therewith. Further, there is provided a polylactic acid resin molded item produced by molding the above polylactic acid resin composition. In the injection molding of the polylactic acid resin composition, the temperature of the metal mold is set so as to range from the glass transition temperature of the polylactic acid resin plus 20 DEG C to the melting point thereof minus 20 DEG C. Thus, there is provided a resin composition enhanced in moldability at the temperature of polylactic acid resin crystallization, and provided a molded item therefrom.