Abstract: Objective: To observe inhibiting BALB/c murine renal carcinoma after radiation.Methods: Annexin-Ⅴ-FITC/PI assay had been used for detect the changes of apoptosis rate after radiation.Animal tumor model had been established.The expression of IL-2 and IFN-γ had been measured with ELESA kit.Results: ①In a definite dose range,apoptosis rate of Renca increased with the elevation of radiation dose.②Tumor regression in radiotherapy was more effective than untreated mice.③The secretion of IL-2 and IFN-γ increased dramatically after radiation.Conclusion: The growth of tumor has been obviously inhibited after radiation,which may caused by radiation-induced apoptosis of Renca cells and the higher ability of secretion of IL-2 and IFN-γ by splenic cells.