Objective:To evaluate the effect of Spirulina platensis polysaccharide (SPP) on hematopoietic recovery and related cytokines in mice with transplanted tumor after chemotherapy. Methods:Mouse model of transplanted solid tumor was established and treated with chemotherapy. Peripheral blood cells, bone marrow nucleated cells, and colony forming unit spleen (CFU S) were counted; the content of DNA in bone marrow was inspected by ultraviolet spectrophotometer; serum content of cytokines, interleukin (IL)1, IL 3, granulocyte macrophage colony stimulating factor (GM CSF) and tumor necrosis factor α (TNF α) were determined by double antibody sandwich ELISA.Results:Cyclophosphamide (CTX) could induce evident myelosuppression, manifested as decrease of peripheral blood cells, bone marrow nucleated cell and DNA, and the CFU S number. SPP could significantly ameliorate the myelosuppression induced by CTX without reducing anti tumor effect of CTX. In addition, it could also increase the contents of IL 1, IL 3, GM CSF, TNF α in serum. Conclusion:SPP can probably accelerate the hematopoietic recovery in mice after chemotherapy through promoting endogenous secretion of cytokines. Objective: To evaluate the effect of Spirulina platensis polysaccharide (SPP) on hematopoietic recovery and related cytokines in mice with transplanted tumor after chemotherapy. Methods: Mouse model of transplanted solid tumor was established and treated with chemotherapy. Peripheral blood cells, bone marrow nucleated cells , and colony forming unit spleen (CFU S) were counted; the content of DNA in bone marrow was inspected by ultraviolet spectrophotometer; serum content of cytokines, interleukin (IL) 1, IL 3, granulocyte macrophage colony stimulating factor Results: Cyclophosphamide (CTX) could be induced as myelosuppression, manifested as decrease of peripheral blood cells, bone marrow nucleated cell and DNA, and the CFU S number. SPP could significantly ameliorate the myelosuppression induced by CTX without reducing anti tumor effect of CTX. In addition, it could also increa se the contents of IL 1, IL 3, GM CSF, TNF α in serum. Conclusion: SPP can probably accelerate the hematopoietic recovery in mice after chemotherapy through promoting endogenous secretion of cytokines.