Abstract： Objective To study the clinical significance of detection for CD25 and CD127 expression on peripheral blood CD4+ T cell subsets in patients with hepatitis B infection. Methods T cells were marked with fluorescence antibodies CD127-FITC, CD4-PECY5, and CD25-PE. Flow cytometry was used to detect the expression of CD25 and CD 127 on CD4+ T cell subsets in 53 patients with chronic hepatitis B (CHB) and other 53 HBV carriers. Twenty HBV-DNA positive patients treated with interferon were followed up. Results Compared with the healthy controls[7.26％ (6.15％, 8.50％)], CHB patients[11.23％(9.10％, 14.86％)]and carriers [13.34％ ( 10.73％, 18.90％)]showed higher level of CD25-CD127- expression on CD4+ T cells with statistical significance (Q=4.559, P＜0.05; Q=6.230, P＜0.05 ). The level of CD25hiCD127low/- expression on CD4+ cells was significantly higher in CHB patients[8.78％ (7.62％, 10.44％)]than that in healthy controls[6.76％ (5.73％,8.23％)]and carriers[6.99％ (5.77％, 9.34％)](Q=3.497, P＜0.05 ; Q=3.103, P＜0.05 ). HBV-DNA positive subjects showed significantly lower expression of CD25-CD 127-[( 12.92±5.20)％ vs ( 15.78±6.91 )％, t=2.290,P=0.024]and higher expression of CD25hiCD127+[(79.27±5.20)％ vs (76.02±7.04)％, t=2.194, P=0.030]on CD4+ T cells than HBV-DNA negative subjects. Compared with baseline, 12-week therapy with interferon resulted in lowered expression of CD25-CD127-[(13.86±5.72)％ vs ( 10.86±3.60)％, t=2.469, P=0.024]and enhanced expression of CD25h1CD127low/-[(9.29±2.51)％ vs (11.08±2.38)％, t=2.820, P=0.011]on CD4+ T cells.Conclusion Expression of CD25-CD127- and CD25hiCD127+ on CD4+ T cells correlates with viral infection and clearance. Exogenous interferon may increase CD25hiCD 127low/- and reduce CD25-CD 127- expression on CD4+ T cells.