Adipose tissue plays a critical role in energy homeostasis,not only in storing triglycer-ides, but also in secreting adipokines that control lipogenesis and lipolysis. Adipocyte functionality is lost during obesity and has been related to adipocyte hypertrophy,disequilibrium between lipogenesis and lipolysis. Thus, understanding the molecular process of lipid metabolism that occurs in adipocytes will provide new tools for the treatment of metabolic abnormalities during obesity. This review discusses the structure and functions of lipid droplets,adipocyte triglyceride metabolism in lipid droplets,lipases and protein associated with lipid metabolism, adipokines and signal pathways.