To observe changes in oxidative stress and effects of dialysis on patients with end stage renal disease (ESRD), vitamin E, GSH, malondialdehyde (MDA) levels in plasma and carbonyl contents of plasma proteins, and blood glutathione peroxidase (GPx) activity were assayed in healthy individuals, chronic renal failure (CRF) patients before dialysis, and after hemodialysis (HD) or peritoneal dialysis (PD). As compare with healthy control, plasma levels of vitamin E and GPx activity of CRF patients were lower, whereas plasma contents of both MDA and carbonyl content of plasma proteins were increased significantly ( P