Abstract: Objective To observe the efficacy and safety of sodium glycididazole（CMNa） in combination with radiotherapy on breast cancer with brain metastasis. Methods Thirty-six breast cancer patients with brain metastasis were enrolled in this study. Sixteen patients were treated with CMNa+radiotherapy（CMNa group），and 20 patients were treated with radiotherapy alone（radiation group）. The total dosage of radiation was 40 Gy／20 f，or 30 Gy／10 f. CMNa was taken 800 mg／m2 three times a week. The response rate（RR），median intracranial progression-free survival（PFS）and side effects were analyzed. Results The RR of CMNa group was 87.5％，and 50.0％ in radiation group，with significant differences（P＜0.05）. The median intracranial PFS of CMNa group was 9.9 months，and 5.3 months in radiation group，with significant differences（P＜0.05）.The main side effects of the two groups were hair loss，headache，nausea/vomitting and leukopenia of grade 1-2（P＞0.05）. Conclusion CMNa in combination with radiotherapy is a feasible and effective treatment for breast cancer with brain metastasis without increase in side effects.