Abstract: Objective: To locate the location and range of neoplasms in visual path using dynamic perimeter. Methods: visual acuity with 60. and 72 dots were checked in 60° and 72 dots were checked in 60 cases of pituitary tumour using American TFS-4000 type sound control dynamic perimeter as compared with CT and MRI checking. Results: The positive rate of visual field before operation was 68.33% and the negative rate was 31.6%. The positive rate of CT and MRI was 70% and 4 cases were normal （6.77%）. Statistic checking showed coherence between the two results, χ²＝0.08，P＞0.05 Although the positive rate of visual field was lower than that of CT and MRI, the diagnostic value of positive visual field was 100% and there was no false poitiveness. 49 eyes of the 120 eyes showed hemianopsia （40.83%）, it was characteristically divided by the central line. The number of hemianopsia was more than defect, blind dots and full blind. Conclusion: The visual field changes of pituitary tumour showed hemianopsia, blind dots, defect etc.. Their location and nature have important significance in early diagnosis, surgical location and surgical path.