Objetive:To evaluate the efficacy of preoperative transcatheter arterial embolization in the treatment of sacral chordoma,and to explore the choice of embolization timing. Methods:32 patients underwent the posterior approach after TAE of the main arteries that supplied the sacral chordoma. Intraoperative bleeding amount of each patient was recorded and compared between-group differences at different operation times. Results: After embolization, 12 patients were received resection within 24 hours (group A),that of 10 cases between 24 ～ 48h (group B), of another 10 cases between 48～ 72h (group C). All of the 32 tumors were removed intact with intraoperative bleeding about (894±199)ml, without any shock or death,nor injuries on abdominal organs such as rectum and ureter. There was no statistical significance in tumor size among group A,B and C (P＞0.05). Data gave statistical significance in intraoperative blood loss between group A and B (P＜0.01) ,there was no statistical differences between group B and C (P＞0.05), in spite of group B slightly less than group C. Conclusion: Preoperative TAE for excising the sacral tumor can significantly decrease intraoperative blood loss, make the surgical field clear,and facilitate the maximal removal of the sacral chordoma. It would be best to select the embolization timing within 24 hours before surgical operation.