Abstract: Objective To study the expression of CD4,CD8,PD-1 and PD-L1 in liver tissues of patients with acute or chronic liver failure（ACLF） due to HBV infection. Methods Liver tissue samples were taken from 10 patients with ACLF due to HBV infection and stained with immunohistochemistry.Ten patients with liver cirrhosis（LC） served as a LC group,and 6 healthy individuals served as a control group.Expression of CD4,CD8,PD-1 and PD-L1 in different liver tissue samples was detected with immunohistochemical staining. Results The expression level of CD4,CD8,PD-1 and PD-L1 was significantly lower in control group than in patients with ACLF due to HBV infection and in LC group（P＜0.05）. Conclusion Elevated PD-1/PD-L1 expression level is related with the exacerbated ACLF due to HBV infection.