Background　Obesity is a pathological state due to over or abnormal accumulation of adipose tissue generated by nutrition metabolism imbalance. Adipose tissue can secrete inflammatory cytokines， termed "adipokines"， which will bring about inflammatory cells infiltration and inflammation status up-regulation， which is presumed to take part in pathogenesis of metabolic diseases. Recent researches show that obesity-induced inflammation will cause metabolic disturbances of sphingosine-1-phosphate（S1P）， which will increase the risk for metabolic diseases including atherosclerosis， type 2 diabetes and non-alcoholic fatty liver disease（NAFLD）.　Objective　To discuss the interaction between obesity-induced inflammation and S1P metabolism.　Content　Pathological process of obesity-induced inflammation， regulation of S1P metabolism， and functions of S1P in the pathogenesis of metabolic diseases.　Trend　To clarify the specific role of S1P in the pathogenesis of obesity-induced inflammation will provide us with molecular targets for preventing and treating metabolic diseases in the future.