Abstract: Objective To observe the characteristics of plasma amino acids in patients with HBVrelated chronic liver disease， and to investigate the relationship between plasma amino acids with the severity of liver disease and to guide the targeting management for the patients. Methods The level of plasma amino acids， liver function， serum NH3 were measured in 35 cases of HBVrelated chronic liver disease and 10 healthy controls were tested as well. The characteristics of amino acid spectrum， especially the changes of citrulline， ornithine and ammonia were analyzed. Results There was no obvious imbalance of plasma amino acids for most of the patients with chronic hepatitis B. But the blood level of aromatic amino acid increased gradually as the disease moved to cirrhosis and liver failure. At the same time， branched chain amino acids / aromatic amino acids ratio decreased significantly. Comparing with the normal control， the blood levels of ornithine， citrulline and NH3 in patients with HBVrelated liver disease increased gradually. Conclusion Plasma amino acids levels may reflect the state of amino acid metabolism in patients with chronic HBVrelated liver disease. Branched chain amino acids / aromatic amino acids ratio， ornithine and citrulline levels may have some value in assessing the disease severity， predicting the  hepatic encephalopathy and guiding the clinical treatment for the liver patients.

Key words: hepatitis B, chronic, liver cirrhosis, acute onchronic liver failure, amino acids