Abstract: Adjuvant temozolomide- based chemotherapy has become the standard of care for most postoperative glioma patients. However, a large proportion of these patients do not respond to temozolomide. DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation has emerged as an important molecular marker in patients with gliomas. It is associated with prognosis and resistance to alkylated drugs such as temozolomide. MGMT promoter methylation is the key mechanism of MGMT gene silencing, thereby inhibiting DNA repair and increasing the sensitivity of chemotherapy. We reviewed current data on the prognostic and predictive relevance of MGMT testing and clinical trials, summarized the clinical application of MGMT promoter methylation, in order to provide reference for the individualized treatment of glioma patients.