Abstract: ¹⁸F-FDGis the most common PET-CTimagingagent, which is widelyused in tumor inaging. Absorption and utilization ofglucose can be controlled bymultiple factors, which are involved in the increase in aerobic glycolysis of tumor.The phenomenon of a general increase uptake of FDG in metastatic tumor may indicate that it is necessary.High glucose metabolism is an important sign of cancer because increased glucose metabolism produces acid, which provide the growth environment to cancer cells.It is important to know the principle of FDG metabolism for accurate image diagnosis.This article reviews the progress of relevant molecular mechanism in recent years.The major molecular mechanism of glucose metabolism associated with tumor FDG uptake include glucose transport and hexokinase, mitochondrial defects, c-myc, hypoxia-inducible factor and so on.