Environmental concerns are pushing industries for the use of renewable and bio-based materials. Considerable interest has been devoted to poly(lactic acid) (PLA) since this polymer has shown promising and excellent results in mechanical and environmental properties. Poly(lactic acid) properties can be improved by incorporation of nanoplatelets , nanofibers, nanocrystals and nanoparticles into polymer matrix. The reinforcement of poly(lactic acid) using these methods has attracted more researchers with the goal of making "green-nanocomposites" due to their extensive and potential applications. This BOOK reviewed the recent advances in the preparations , modification, fabrication and properties of poly(lactic acid) nanocomposites.