BACKGROUND: B-cell may participate in the cellular immune process of hepatitis B antigen clearance. However, the function and specific mechanism of B-cell during interferon-pegylated interferon α-2a (Peg-IFN-α) treatment in chronic hepatitis B (CHB) patients have not yet been described. METHODS: A total of 150 CHB patients enrolled in this study, who received 48 weeks of Peg-IFN α treatment. The differentiation clusters CD19, CD24, CD27, CD38, CD40, and CD80 of B cell surface markers in CHB patients were detected by flow cytometry. Spearman correlation and Logistic regression analysis were performed for the analysis. RESULTS: The clearance rate of HBsAg increased significantly with the duration of Peg-IFN-α treatment, reaching 32.2% by 48 weeks. During the Peg-IFN-α therapy, the frequency of B-cell and its subsets increased significantly. However, we did not observe any significant difference in the frequency of the B-cell and its subsets in patients with or without HBsAg clearance after 48 weeks Peg-IFN-α treatment. The change in HBsAg value was negatively related to the change in plasmablasts (CD19 CONCLUSION: The remodeling of B cell subsets, especially plasmablasts (CD19