Genes are DNA segments with genetic effects, which are intrinsic determinants of life and health, and genetic alterations are the root cause of tumors. Genetic testing is a technique to detect DNA through tumor tissues, blood, and other body fluids, and through genetic testing we can obtain information about genetic mutations. The latest 2016 World Health Organization (WHO) guidelines for central nervous system tumors introduced molecular pathology into the diagnosis of glioma, and the diagnostic report of glioma now consists of two parts: histopathological diagnosis and molecular pathological diagnosis. Histopathology can clarify whether the lesion is a glioma and its degree of malignancy. Molecular pathology is the genetic testing to identify the mutation characteristics of the tumor, which can help to classify the tumor subtype, prognosis assessment, and suggest the sensitivity of radiotherapy, thus guiding the formulation of radiotherapy, targeted therapy and other treatment plans. Overall, genetic testing can provide an important basis for glioma staging, treatment and prognosis assessment. At present, the main genes tested for glioma include IDH, 1p19q, MGMT, TERT, EGFR, TP53, BRAF and so on. In terms of staging, if there is a combined IDH mutation + 1p19q deletion, then this patient we can diagnose as oligodendroglial cell tumor, this type of glioma is sensitive to radiotherapy and is the type with the best prognosis for diffuse glioma. In terms of prognostic assessment, most patients with mutations in IDH have a better prognosis than those without mutations, and most patients with positive MGMT promoter methylation have a better prognosis than those with negative ones, which is the worst kind of prognosis if TERT mutations alone are present. In terms of drug selection, patients with positive MGMT promoter methylation are sensitive to temozolomide. Negative patients are poorly sensitized. In addition if more genetic testing programs are done, we can select from them the targeted drugs that may be effective. For example, if there is no better way for tumor recurrence, with BRAF mutation we can try verofenib treatment, and with high VEGF expression we can try anti-angiogenic drugs as adjuvant therapy, etc. In addition, genetic testing is also one of the methods to assess the effectiveness of immunotherapy.