Objective: To study the effects of L-carnitine on the erythrocyte immune function in peritoneal dialysis patients with chronic renal failure. Methods: Twenty-three peritoneal dialysis patients with chronic renal failure were randomly divided into 2 groups. Forteen patients were given L-carnitine oraly with a dosage of 2 g /d, while the 9 control patients were given normal saline . Results: The state of erythrocyte immune function including the rossette rate of C3b receptor and rossette rate of tumour cell were increased significantly (P＜0.05), and the serum oxygenize LDL decreased significantly (P＜0.05).Conclusion: Supplement of L-carnitine can improve the erythrocyte immune in peritoneal dialysis patients.