Chronic hepatitis B virus (HBV) carrier status has a critical impact on clinical management of patients with IgA nephropathy (IgAN) who are treated with corticosteroids, because corticosteroids may enhance HBV replication. This study compared corticosteroids and antivirals combined therapy with corticosteroids monotherapy on patients of IgAN who were also HBV carriers. This was a prospective, open-label cohort study on Chinese adults of HBV inactive carriers with concurrent IgAN (proteinuria a parts per thousand yen3.5 g/day). The patients were self-assigned to combined therapy group (prednisolone + lamivudine) or monotherapy group (prednisolone). Prednisolone 1 mg/kg/day for 2 months, tapered gradually, duration 12 months. Lamivudine (100 mg/day) was administrated 2 weeks before starting prednisolone and maintained 6 months after prednisolone withdrawal. All patients were followed up for 18 months. Outcome measures were rates of complete remission of proteinuria (< 0.5 g/day), persistent massive proteinuria (a parts per thousand yen3.5 g/day), HBV reactivation (detectable serum HBV-DNA or HBeAg), and significant alanine aminotransferase (ALT) elevation (> 120 mu/L). Except 3 patients were lost to follow-up, 46 patients (29 of combined therapy group, 17 of monotherapy group) were included in the analysis. There were no differences in baseline characteristics of clinical and histopathological features between two groups (p > 0.05). At the end of follow-up, 19/29 (65.52 %) in combined therapy group and 9/17 (52.94 %) in monotherapy group achieved complete remission of proteinuria (p = 0.399), while 0/29 (0 %) and 2/17 (11.76 %) remained persistent massive proteinuria (p = 0.059). HBV reactivation and significant ALT elevation was 3/17 (17.65 %) of patients in monotherapy group, more than 0/29 (0 %) of combined therapy group (p = 0.019). Three HBV recurrent patients using prednisolone monotherapy were all male and young, with relatively short term of HBV infection history, HBV reactivation and severe liver impairment developed after 3 months of corticosteroids treatment, and daily proteinuria increased remarkably after prednisolone withdrawal. This study successfully treated with combined lamivudine and prednisolone in inactive HBV carriers with IgAN. We believe the combination of prednisolone and lamivudine was more efficacious than prednisolone alone in providing long-term viral suppression and liver enzyme normalization in inactive HBV carrier with IgAN.