Objective To summarize the experience of 74 patients with brain tumors whose pyramidal tracts were visualized by diffusion tensor imaging(DTI)based fiber tracking(FT)during perioperative period.Methods All the patients received MRI scans preoperatively and intraoperatively.Pyramidal tracts were constructed and integrated into neuronavigation system to implement fiber tracts navigation.The outcome,modification for strategy of surgery and factors influencing the protection for pyramidal tract were summarized.Results Before operation,the distance between pyramidal tract and tumor was ranged from 0 nun to 5 mm in 36 cases.27 among the 36 cases had motor deficits.The distance in 12 cases was ranged from 5 mm to 10 mm and two had motor deficits among them.The distance was greater than 10 mm in 26 cases and none of them had motor deficits.After operation,motor deficits were improved in 7 cases.no change in 48,14 developed new postoperative deficits and paresis was observed in 5 cases.The paresis was resolved partially in the prolonged postoperative course in 3 eases.The maximal pyramidal tract shifting Was ranged from-16.2 mm to+17.2 mm.Conclutions Pyramidal tract navigation can help surgeon to choose right snrgical approach,to lower the risk of surgery and determine the extent of resection.Thus,the rate of severe motor deficits could be decreased.The shifting of pyramidal tract during operation is irregular.Intraoperative MRI scan is necessary for detection of the shifting.