Metabolic syndrome is a growing research area.The underlying mechanisms of metabolic syndrome are still not very clear.Insulin resistance,obesity,inflammation and oxidative stress may play an important role in the pathogenesis of metabolic syndrome.The role of adipose tissue dysfunction is emphasized during the development of obesity.Adipose tissue is identified as a complex endocrine organ and its metabolic functions extend well beyond the classical actions of thermoregulation and of storage and release of fatty acids.Chronic low-grade inflammation activated by the immune system in adipose tissue is a key contributing factor to type 2 diabetes mellitus and cardiovascular diseases.Visceral obesity results in cell autonomous impairment in insulin signaling that leads to insulin resistance.Chronic inflammation in adipose tissue has gained acceptance as a lead promoter of insulin resistance in obesity.Furthermore,obesity creates oxidative stress conditions in adipose tissue that not only correlates with insulin resistance but is also causative in its development.Oxidative stress may be a mechanistic link between several components of metabolic syndrome and cardiovascular diseases,through its role in inflammation and its ability to disrupt insulin-signaling.The study around adipose tissue dysfunction will help to understand the pathogenesis of metabolic syndrome and may bring effective therapy in treatment of metabolic syndrome related diseases.Therefore,this review mainly focuses on the roles of adipose tissue dysfunction in inflammation,insulin resistance,and oxidative stress in the pathogenesis of metabolic syndrome.