Abstract: OBJECTIVE To investigate toxicity attenuation of chemotherapy and radiotherapy with Stronger Neo-Minophagen C Injection(SNMCI) and explore the new value of SNMCI for clinical application. METHODS Normal and S180 inoculated mice were divided randomly into low, medium and high dose groups of SNMCI. SNMCI were intravenously-administrated with the dosage of 40, 20 and 10 mg·kg^-1(calculated as dosage of glycyrrhizin) to the groups of mice, respectively, once per day for 7 days. Mice were treated with chemotherapy (cyclophosphamide, 100 mg·kg^-1, ip) and radiotherapy(⁶⁰Co, 5.0 Gy). On 8th day, mice were sacrificed. And then body weight, thymus index, spleen index, periphery blood of WBC, bone marrow nucleated cells were observed. RESULTS ①Chemotherapy could significant reduce thymus index, spleen index, periphery blood of WBC, bone marrow nucleated cells in both normal and S180 inoculated mice(P<0.01). High dose group of SNMCI significantly increased periphery blood of WBC and bone marrow nucleated cells compared with chemotherapy group(P<0.05), medium and low dose groups also had some improvement. Three doses of SNMCI had poor improvement on thymus index and spleen index. ②Radiotherapy could significantly reduce thymus index, spleen index, periphery blood of WBC, bone marrow nucleated cells in both normal and S180 inoculated mice(P<0.01). Three doses of SNMCI had poor improvement on lesion induced by radiotherapy. CONCLUSION SNMCI can significantly improve myelosuppression induced by cyclophosphamide in normal and S180 inoculated mice while has poor improvement for myelosuppression induced by ⁶⁰Co radiation. The present findings suggest that SNMCI is valuable for myelosuppression induced by chemotherapy.