Malignant tumor has been a major diseases threat to human health, with current social habits, diet, living environment and other factors changing, the incidence of malignant tumors have also undergone significant changes. The set of diabetes/ hyperglycemia, hyperlipidemia and hypertension, which is obesity, has been a risk factor for many kinds of major diseases. A growing number of studies confirmed that a variety of malignant tumor associated with MetS, MetS and malignant tumor have been a global problem threatened human health. In recent years, the further researche of basic medical sciences and epidemiology on MetS-induced malignant tumor clarified the intimate relationship between MetS and malignancy, each factor of MetS is interrelated, the accumulation of individual factors increased the risk of cancer and mortality. With further research, the molecular mechanisms are gradually discovered, the molecular mechanism which accumulation of risk factors induced tumor is more explicit, possible mechanisms include: the role of long-term hyperglycemia, obesity and hyperlipidemia, the role of insulin factor and secretion factor interferences which coordinate the action, and the prevention and treatment in clinical of tumor is also gradually improved. This review will describe the association between metabolic syndrome and malignant tumor from the points of the epidemiology and molecular mechanism based on recent years related research.