Abstract: To study the characterestics of the expression of Fas and FasL in the liver tissue of chronic hepatitis B (CHB) . Liver biopsy samples from 30 CHB were fixed in formaldehyde and embedded in paraffin. The liver specimens were immunohistostained by SP method (1) Fas antigen and FasLs specific positive signals were found mainly on the surface or/ and in the cytoplasm of the hepatocytes, these positive hepatocytes were scattered nearby periportal region and hepatic lobule with piecemeal necrosis, the infiltrating lymphocytes were mainly FasL-positive cells. (2) The expression of Fas antigen or FasL was correlated with the degree of CHB that is the grade of inflammatory activity (G) and the stage of fibrosis of liver tissue (S) ( P <0 001) . There were Fas and FasL expressions in the liver tissue of CHB which were strongly positive accord with the degree of CHB that is the grade of inflammatory activity (G) and the stage of fibrosis of liver tissue (S) . Fas/FasL-induced apoptosis contributed to pathogenesis of CHB and play an important role on the progression of CHB.