Abstract: Objective To investigate the expression characteristics of Treg,Tr1,and Th17 cells in the peripheral blood of patients with chronic hepatitis B( CHB) and their correlations with the state of CHB. Methods A total of 40 patients with mild- to- moderate CHB and40 patients with severe CHB who were admitted to The 180 th Hospital of PLA from January 2013 to June 2014 were included into this study,and 40 healthy people with normal liver function were recruited as control group. Peripheral blood was collected from CHB patients and healthy controls,and then the percentages of Treg,Tr1,and Th17 cells in peripheral blood were determined by flow cytometry. The levels of Foxp3 mRNA and RORγt mRNA in serum were measured by real- time PCR,and the expression levels of TGF- β1,IL- 10,and IL-17 were measured by ELISA. Comparison of continuous data between the groups was made by one- way ANOVA analysis and LSD- t test.Results( 1) Compared with the control group,the two groups of CHB patients had significantly higher percentages of Tr1,Treg,and Th17cells( P < 0. 05),and had significantly higher levels of Foxp3 mRNA and RORγt mRNA( P < 0. 05) and levels of TGF- β1,IL- 10,and IL- 17( P < 0. 05),while the two groups of CHB patients had significantly lower Treg / Th17 ratio( P < 0. 05) and Foxp3 / RORγt ratio( P< 0. 05) than the healthy controls.( 2) The patients with severe CHB had significantly higher percentages of Treg,Tr1,and Th17 cells( P< 0. 05),and had significantly higher levels of Foxp3 mRNA and RORγt mRNA( P < 0. 05) and levels of TGF- β1,IL- 10,and IL- 17( P < 0. 05),as compared with the patients with mild- to- moderate CHB,while the patients with severe CHB had significantly lower Treg/Th17 ratio( P < 0. 05) and Foxp3 / RORγt ratio( P < 0. 05) than those with mild- to- moderate CHB. Conclusion The expression imbalance of Treg cells( especially Tr1 cells) and Th17 cells in CHB patients is positively correlated with the progression of the disease; therefore,it may be important to correct the expression imbalance of Treg cells and Th17 cells in the treatment of CHB. Meanwhile,monitoring the percentages of Treg cells( especially Tr1 cells) and Th17 cells is helpful for assessing the clinical outcomes of CHB patients and guiding the clinical treatment.