Introduction: Children with IgA vasculitis with nephritis (IgAVN) usually accepted TCM combined with western medicine therapy, but its effect on immune function is not clear, here is to analyze the change of peripheral blood CD19+ B lymphocytes in children with IgAVN after treatment of TCM combined with AECI or/and immunosuppressive agents. Methods: 46 children with IgAVN diagnosed from Apr. 2016 to Apr. 2017 were included and followed up in out-patient department till Dec 2021. All children with IgAVN were treated with TCM combined with ACEI or/and glucocorticoid steroids, with/without glucocorticoid-sparing agents. During treatment, urinary erythrocytes / urinary protein, peripheral blood CD (cluster of differentiation) of lymphocytes and serum Igs were tested before and after treatment. Results: All children with IgAVN except one were complete remission and no child progressed to CKD after 5-6 years follow-up. The counts of CD19+ B lymphocytes and CD19+ % in children with complete remission were significantly reduced after TCM combined with ACEI or/and glucocorticoid steroids with/without glucocorticoid-sparing agent (P < 0.01), the levels of serum IgA in children with complete remission and partial remission after 6 mo combined therapy were significantly decreased (P < 0.01, P < 0.05), and IgM in partial remission children after 6 mo combined therapy was significantly lower (P < 0.05). Conclusion: Peripheral blood CD19+ B lymphocytes in children with IgAVN decreased when it gained remission with treatment of TCM combined with ACEI or/and glucocorticoid steroids with/without glucocorticoid-sparing agent, suggesting that change of peripheral blood CD19+ B lymphocytes could be used to evaluate effect of therapy.