Aim To investigate possible oxidative injuries topatients during hemodialysis process with differentmembranes.Method The levels of malondialdehyde(MDA)andsuperoxide dismutase (SOD) in both plasma and redblood cell, gultathione peroxidase (GPX) in whole blood samples of maintenance hemodialyzed patientswere exanlined before and after dialysis with cupo-phane, polysulphone and hemophan membranes,and were compared with those of health controls.Result A significant increase of MDA level and adecrease of SOD activity after dialysis with cupophane membrane, while no significant differences were ob-served with polysulphone and hemophan membranes.Conclusion The use of polysulphone and hemophan membranes for long term hemodialysis is benefit to Prevention and cure any syndrome caused by the in-crease of peroxide radicals.