Abstract: Objective : Reinvestigating frozen sections of 3000 cases of CNS disease; Analyzing pathologic characters of misdiagnosis case. Concluding the important and difficult points of frozen sec-tion diagnosis on CNS disease. Methods : The frozen sections of 3000 cases CNS disease are analyzed by comparing the frozen section with paraffin section and clinical data. Results : The accurate rate of frozen section diagnosis is 95.87%, the misdiagnosis rate is 4.13% in this material. The highest misdi-agnosis rate tumors are meningeal mesoderm sarcoma、haemangioblastoma, lymphoma、oligoden-droglioma, et al. Conclusions : The conect frozen section diagnosis needs to have enough samples and clinical data; Pathologic doctor must learn more basic pathological knowledge and rich experience on frozen section and clinic 、 radiographic knowledge, in order to ensure correct diagnosis.