Abstract: Glioma is the most common primary brain tumor, accounting for about 40%-50% of intracranial tumors. Patients have a poor prognosis and especially high-grade glioma. With various characteristics of histology and multiple biological behaviors, glioma has different responses to many types of treatment. CT and MRI are conventional imaging methods, while PET or PET/CT is relatively new. The latter mainly reflects tumor metabolism. CT reflects anatomy structure by utilizing the difference of tissue density. However, CT cannot estimate tumor metabolism. Although MRI has good tissue resolution and can also judge tumor metabolism, it still has some limitations. With the extensive use of ¹⁸F-FDG PET or PET/CT and the development of other imaging agents beyond FDG, the diagnostic value of PET or PET/CT in glioma is highly concerned.