Abstract: Acne is a chronic inflammatory disease of the pilosebaceous unit with predilection for adolescents. Hormones are the most important endogenous factor for the occurrence of acne. Recently, it has been found that besides androgen, insulin resistance and abnormal levels of insulin and insulin?like growth factor?1(IGF?1)induced by insulin resistance were closely associated with acne. Concretely speaking, insulin and IGF?1 may participate in the occurrence of acne by indirectly stimulating androgen secretion and directly inducing keratinocyte proliferation, sebaceous lipogenesis and inflammatory responses. In addition, the fact that acne is an important clinical characteristic of some systemic diseases or syndromes, such as polycystic ovary syndrome(PCOS)and hyperandrogenism?insulin resistance?acanthosis nigricans (HAIR?AN)syndrome, and associations of acne with diet, smoking and tumors, all provide evidence for the potential role of insulin resistance in the occurrence of acne.