The zinc finger protein A20 is a newly identified negative regulator of immune response and mediates signal pathway of NF-κB in liver inflammation. However, the role of A20 in the natural history of patients with chronic hepatitis B (CHB) has not been demonstrated. In this present study, we aimed to investigate the dynamic expression of A20 and determine the potential association of A20 in the progression of chronic hepatitis B virus infection.This retrospective study contained 136 patients with chronic hepatitis B and 30 healthy controls (HCs). The mRNA level of A20, TNF-α, NF-κB p65 and toll-like receptor (TLR) 4 in peripheral blood mononuclear cells (PBMCs) was determined using a relative quantitative real-time polymerase chain reaction. The hepatic A20 protein expression was determined by immunohistochemistry. Clinical and laboratory parameters were obtained.In the present study, the relative expression of A20 mRNA was significantly increased in CHB patients compared with HCs and was positively associated with alanine aminotransferase, aspartate aminotransferase, and total bilirubin. In CHB patients, the levels of A20 mRNA in the immune clearance (IC) phase and hepatitis B negative (ENH) phase were significantly higher than that in immune tolerance (IT) phase and low-replicative (LR) phase (P < 0.001). Furthermore, the A20 mRNA level was significantly correlated with TNF-α/ NF-κB p65/TLR4 mRNA levels in CHB patients. Of note, we reported that cutoff values of 4.19 and 3.97 for the level of A20 mRNA have significant power in discriminating IC from IT, and ENH from LR in CHB patients respectively.In conclusion, our results suggested that increased levels of A20 mRNA and protein contribute to disease progression of chronic hepatitis B virus infection.