Abstract: Objective To study the value of homocysteine（Hcy） in diagnosis of liver diseases.Methods Different serum ALT,AST,ALB,TBA,TB,and Hcy levels were observed in 37 patients with hepatitis B,29 patients with liver cirrhosis（LC）,45 patients with primary hepatocellular carcinoma（HCC）,and 35 normal controls.The sensitivity and specificity of Hcy in diagnosis of primary HCC were analyzed.Results No statistical difference was found in serum ALB,TBA and Hcy levels between patients with hepatitis B and those with LC（P＞0.05）.However,a statistical difference was found in other biochemical indicators between patients with hepatitis B and those with LC（P＜0.05）.The Hcy level was positively correlated with the AST and TB level.The area under the ROC curve was 0.70 when Hcy was used in diagnosis of HCC,with sensitivity of 62.2% and a specificity of 94.3% when the critical value was set at 0.14.Conclusion Hcy can be used as a biochemical marker of liver diseases and has a certain value in diagnosis of primary HCC.