Objective To observe the role of low-protein diet and combination withα-ketoacid therapy in improving nutritional status of patients with continuous ambulatory peritoneal dialysis(CAPD) prospectively. Methods Seventy-eight CAPD patients were investigated and followed-up for one year. They were randomly assigned to a low-protein diet supplemented with α-ketoacid group(ketoacid group), low-protein diet group and routine protein diet group. The serum levels of albumin(Alb), prealbumin(PA), transferring(TF), retinal-binding-protein(RBP)，total cholesteral(TC)， griglyceride (TG)，Leptin were measured. Triceps skinfoles (TSF),midarm riuscle circumference(MAMC), body mass index(BMI), residual renal function(RRF), Kt/V, clearance of creatinine(Ccr) and levels of serum amino acids were performed. Results Compared to low-protein diet group, serum levels of PA, RBP, TRF had a significant increment both in ketoacid group and routine protein diet group (P ＜0.01), but there was no significance between these two groups(P＞0.05). There was an incremental tendency in Alb, TC, TG, but no significance(P ＞0.05). The serum concentrations of Valine(Val), Leucine(Leu), Isoleucine(Ile) were significantly increased in ketoacid group (P ＜0.01), compared to the other groups. Levels of KT/V, Ccr, residual urine volume were significantly higher both in ketoacid group and routine protein diet group(P ＜0.01). Conclusions Low-protein diet and combination withα-ketoacid therapy have a tendency of relieving malnutritional status and improving the levels of BCAA.