Glioma grades 1 to 2 are benign, and grades 3 to 4 are malignant. Clinically, gliomas of one grade only rarely appear, usually grades 1 to 2 are biased toward grade 1 or 2, grades 2 to 3 are biased toward grade 2 or 3, and grades 3 to 4 can be classified as biased toward grade 3 or 4. The pathological examination report of glioma plays an important role in the selection of glioma treatment plan, assessment of treatment effect, and prognosis of glioma. Glioma classification is based on the degree of malignancy of astrocytoma, and the general WHO classification is based on atypicality, nuclear division index, endothelial cell proliferation and necrosis into 4 grades: Grade 1, generally benign, is dominated by hairy cell astrocytes, accounting for about 5% of gliomas, and can be treated well; Grade 2, generally astrocytoma or astro-oligodendroglioma, accounting for about 30-40% of gliomas. It accounts for about 30-40% of glioma. Grade 3, generally mesenchymal astrocytoma, accounts for about 15-25% of gliomas, and generally evolves from grade 2. Grade 4, generally glioblastoma, accounts for about 1/3 of gliomas. Low-grade glioblastoma can be divided into hairy cell astrocytoma (WHO-defined grade I), low-grade diffuse astrocytoma (WHO-defined grade II), oligodendroglioma, oligodendroglioma-astrocytoma, ventricular meningioma, hairy cell type or naive cell astrocytoma; high-grade glioblastoma can be divided into medulloblastoma, mesenchymal astrocytoma and pleomorphic glioblastoma.