Intravenous supplement of essential amino acids (EAA) 12.6 g/d, fortified with branched-chain amino acids, was given to Group A, 5 patients with chronic renal failure (CRF) (mean creatinine clearance rate 6.55±2.49 ml/min) for 14 days on the basis of low protein diet (0.6 g/kg/d) , and Group B, 4 patients with CRF (mean creatinine clearance rate 9.75±3.93 ml/min) for JO days on the basis of low protein diet(0.4g/kg/d). The nitrogen balance, whole body nitrogen flux and rates of protein synthesis and catabolism and amino nitrogen utilization were markedly improved as compared with the pre-treatment levels. With treatment, the levels of some EAA in plasma such as valine, isoleucine, phenylalanine, lysine and methionine were increased, while that of tyrosine was not changed. In 4 of the Group A patients, blood urea nitrogen, creatinine and phosphate were slightly decreased after treatment, while serum calcium level was significontly increased. In 8 patients uremic symptoms were markedly ameliorated and their nutritional status apparently improved. Intravenous supplement of essential amino acids (EAA) 12.6 g / d, fortified with branched-chain amino acids, was given to Group A, 5 patients with chronic renal failure (CRF) (mean creatinine clearance rate 6.55 ± 2.49 ml / min) 14 days on the basis of low protein diet (0.6 g / kg / d), and Group B, 4 patients with CRF (mean creatinine clearance rate 9.75 ± 3.93 ml / min) for JO days on the basis of low protein diet g / kg / d). The nitrogen balance, whole body nitrogen flux and rates of protein synthesis and catabolism and amino nitrogen utilization were markedly improved as compared with the pre-treatment levels. With treatment, the levels of some EAA in plasma such as In 4 of the Group A patients, blood urea nitrogen, creatinine and phosphate were slightly decreased after treatment, while serum calcium level was significantly increased. In 8 patients uremic symptoms were markedly ameliorated and their nutritional status apparently improved.