To explore the expression of Fas/Fas L in liver tissue of hepatitis gravis patients and its implication in hepatocyte apoptosis, Fas/Fas L expression and cell apoptosis was detected by the means of inmmunohistochemistry and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling . It was found that in the 20 patients with clinical hepatitis gravis, Fas in hepatocytes showed strong expression and Fas L also showed intensive expression in infiltrating lymphocytes and scattering hepatocytes. The apoptosis existed in all the samples, scattering in the area of inflammatory, necrotic area and hepatic lobule. It was suggested that the overexpression of Fas/Fas L could cause the death of hepatocytes and thus the occurrence of hepatitis gravis. The apoptosis caused by Fas might be one of the important pathogeneses of hepatitis gravis. Among the detected samples, apoptosis and necrosis coexisted, indicating that both two types of cellular death were closely associated with the pathogenesis of hepatitis gravis. To explore the expression of Fas / Fas L in liver tissue of hepatitis gravis patients and its implication in hepatocyte apoptosis, Fas / Fas L expression and cell apoptosis was detected by the means of inunohistochemistry and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. It was found that in the 20 patients with clinical hepatitis gravis, Fas in hepatocytes showed strong expression and Fas L also showed intensive expression in infiltrating lymphocytes and scattering hepatocytes. The apoptosis was in all the samples, scattering in the area of ​​inflammatory, necrotic area and hepatic It was suggested that the overexpression of Fas / Fas L could cause the death of hepatocytes and thus the occurrence of hepatitis gravis. The apoptosis caused by may might one of the important pathogeneses of hepatitis gravis. Among the detected samples, apoptosis and necrosis coexisted, indicating that both two types of cellular death were closely associated with the pathogenesis of hepatitis gravis.