Since leptin was discovered in 1994, we considered the adipose tissue was not a "stockroom" with energy and being the endocrine-organ which secretes a various hormone, as called adipokine, which has various physiological activity. Much research was done about the effect of adipokine to each organ and disease concept of metabolic syndrome was established that induces metabolic disorders and atherosclerotic diseases by dysregulation of adipokine following visceral fat accumulation. Also, role of adipokine in bone metabolism becomes clear gradually. In this review, former knowledge is outlined mainly about leptin and adiponectin.