Several types of PLA-PEG-PLA triblock copolymers with different molecular weight of PEG segment were synthesized by a ring-opening anion polymerization and were used as hydrophilic additives for PLA hollow fiber membranes.Effects of PLA-PEG-PLA copolymer addition on membrane morphology and performance were studied.Fouling experiments using BSA indicated that antifouling properties of PLA hollow fiber membranes were remarkably improved by addition of PLA-PEG-PLA copolymers.