OBJECTIVE: To evaluate the effect of Fuzhengpaidu granule (FZPDG) on immune activation molecules CD38 and human leukocyte antigen-D related (HLA-DR) on CD4+ and CD8+ cells in HIV/AIDS patients, and to explore the underlying mechanism of this therapy. METHODS: Plasma changes in CD3+, CD4+, CD8+, CD3+CD4+CD38+, CD3+CD4+HLA-DR+, CD3+ CD8+CD38+, and CD3+CD8+HLA-DR+levels in HIV/ AIDS patients treated with FZPDG for six months were examined by flow cytometry and compared with levels in healthy controls. RESULTS: The clinical trial included 34 outpatients with HIV/AIDS. Before treatment, plasma levels of CD38+ and HLA-DR+ on CD4/CD8 cells were higherthan those in 28 health controls (P<0.05). There were no significant changes in serum levels of CD3+, CD4+, and CD8+ T cells between pretreatment baseline versus after treatment, which were 82.85% ± 5.41% , 14.57% ± 10.31% and 54.55% ± 11.43% before treatment and 79.15% ± 8.21% , 19.96% ± 9.58% and 56.36% ± 11.67% after treatment, respectively (P>0.05). Plasma levels of CD3+ CD4+CD38+and CD3+CD4+HLA-DR+were 2.3%± 2.2% and 7.8%±5.5% before treatment and 1.2%± 0.8% and 2.6%±1.0% after treatment, respectively. Plasma levels of CD3+CD8+CD38+ and CD3+CD8+ HLA-DR+ were 41.4%±13.4% and 17.8%±11.3% beforetreatment,whichchangedto27.1%±10.2%and 3.8%±2.4%aftertreatment,respectively(P<0.05). CONCLUSION: HIV/AIDS patients exhibited an immune activation profile following FZPDG treatment. A potential mechanism of action for FZPDG appears to lie in its ability to up-regulate CD38 and HLA-DR levels on CD4+ T cells, and down-regulate them on CD8+ cells, thereby modulating immune activation of CD4+and CD8+T cells.