Abstract: The recent development of research of poly (lactic acid) toughened by non-biodegradable thermoplastic elastomer (TPE), including ethylene, styrene, glycidyl methacrylate and acrylate copolymers, is reviewed. The effects of the species, content and microstructure of TPE as well as interfacial adhesion on the toughness of TPE/PLA blends are emphasized. The research direction in future is also suggested based on the problems in toughening PLA by TPE.