Abstract: Objective To study the correlationship between the expression of programmed death 1 (PD-1) and the pathology of chronic hepatitis B, and explore the role of PD-1 in chronic HBV infection. Methods Liver biopsies were performed in all 84 patients with chronic hepatitis B, the liver tissues were fixed by 10% formalin and paraffin-embedded sections were stained by HE, and the hepatic inflammatory activity grade and fibrosis stages were evaluated. Immunohistochemical SP was applied to detect the expression of PD-1 in liver tissues. The positive expression means that red staining was found in five discontinuous visual fields under high magnification (400 ×). The results were analyzed by Image Pro Plus 6.0 software. The expression intensity of PD-1 in liver tissues were measured by integral optical density (IOD) titres. Results The expression of PD-1 was positively correlated with hepatic inflammatory activity grade and fibrosis stage, with correlation coefficient as 0.898 (P ＜ 0.001) and 0.700 (P ＜ 0.01) respectively. There were significant differences of PD-1 expression among the hepatic inflammatory activity grades of each groups (P ＜ 0.05). The expression of PD-1 were significantly different among the fibrosis stages of each group  (P ＜ 0.05), except S2  and S3 , S3  and S4  (P ＞ 0.05). Conclusions PD-1 expression in liver tissues are positively correlated with the hepatic inflammatory activity grade and fibrosis stage. Detection of PD-1 is worthy of evaluating hepatic inflammatory activity and fibrosis stages, meanwhile, it can provide valuable reference for assessment in hepatitic pathology.