disclosed is a polypropylene - polylactic acid composite composition , in which a maleic anhydride grafted ethylene - octene copolymer is included as a compatiblilizer . since the provided polylactic acid composite composition includes the biomaterial polylactic acid resin , it is capable of effectively reducing carbon dioxide emission . hence , it goes along with the low - carbon , green growth initiative . further , with improved mechanical strength and heat resistance , it is usefully applicable to automotive interiors / exteriors , construction interiors , etc .