The immunoenhancement of compound polysaccharides, APS-sEPS composed with astragalus polysaccharide (APS) and sulfated epimedium polysaccharide (sEPS). was observed in immunosuppressed model chicken induced by cyclophosphamide (Cy). 11-day-old chickens were injected with Cy once a day for three successive days except vaccine control group. At day-14-old, all chickens were vaccinated with ND vaccine, and in experimental groups simultaneously administrated with APS-sEPS at three dosages, APS and sEPS once a day for three successive days. On days 7, 14, 21 and 28 after the administration, the peripheral T-lymphocyte proliferation, serum antibody titers, IFN-gamma, IL-2, IgG and IgM were determined. The results displayed that APS-sEPS could overcome Cy-induced immunosuppression, significantly promote T-lymphocyte proliferation and raised serum antibody titers, IFN-gamma, IL-2, IgG and IgM levels, its high and medium doses were superior to single APS or sEPS. This demonstrated that APS and sEPS could synergistically resist the immunosuppression and APS-sEPS was an effective immunopotentiator. (C) 2012 Elsevier Ltd. All rights reserved.