Abstract: Objective: To improve the level of early diagnoses of the pituitary adenoma,through studying vision function damage and the reason why misdiagnoses taken place to the patients suffered from pituitary adenoma.Methods: Clinical analysis was done on 37 patients who have been confirmed suffering from pituitary adenoma through pathologic diagnosis.Results: Through clinical observation to the 37 patients,there are 35 patients whose vision function were damaged and there are 34 patients whose vision field were damaged,15 patients came to see ophthalmologists because they took the reduce of vision acuity as the first symptom,5 patients were misdiagnosed.Conclusions: During clinical diagnoses,the ophthalmologists should do synthetical analysis to the patients who have abnormal vision acuity and vision field,in order to avoid or reduce the misdiagnoses to the pituitary adenoma.