Methods: 58 chronic hepatitis B patients with both positive for HBsAg and HBsAb were studied.Serological markers of HBV were detected by ELISA and microparticle enzyme immunoassay. HBV DNA levels were determined by fluorescent quantitative PCR, S gene fragments were directly sequenced, liver function was analyzed by automatic biochemistry analyzer AU400. Correlation test was conducted to evaluate their dependablity. Conclusion: Overexpression of PD-1 and PD-L within liver might be involved in inhibiting the immune response and be a mechanism of chronicity in HBV infection.