Abstract: Positron emission tomography(PET) is widely used in early diagnosis, staging, post-treatment follow-up of malignant tumors as well as the differentiation between benign and malignant tumor. So far, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) is the most popular and mature PET tracer according to its excellent performance in various types of cancer. But in some kind of cancers, ¹⁸F-FDG fails to accurately diagnose them. Now with the clinical application of non-glucose metabolic PET tracers like ¹¹C-methionine (¹¹C-MET), ¹¹C-acetate、¹¹C-choline and ¹⁸F-fluorodeoxythymidine(¹⁸F-FLT), they complement ¹⁸F-FDG in improving the sensitivity, specificity and accuracy of tumor diagnosis.