Abstract: Two functions of testis are sperm production and steroidogenesis. Those hormones related to male reproduction include testosterone，follicle stimulating hormone，luteinizing hormone，estradiol and prolactin. Diabetes mellitus（DM） is the metabolic syndrome characterized by hyperglycaemia due to insufficient insulin，which is accompanied by metabolic disorders of fat，protein，water and electrolyte. More than 90% DM are type 2 diabetes（T2DM）. Long-term diabetes can lead to dysfunction and chronic damage in various tissues，especially in eye, kidney，heart，blood vessel and nerve. Male patients with DM are often accompanied with dysfunction of reproductive endocrinology. Androgen level in male DM patients is lower than that in normal men. The symptoms in those patients with lowered hormones include erectile dysfunction and loss of libido, while the metabolic disorders were aggravated by physiological and biochemical mechanisms. All those risk factors are related to atherosclerosis and coronary heart disease（CHD）. We herein reviewed the dysfunction of male reproductive endocrinology in patients with DM，so as to provide reference for the treatment of diabetes.

Key words: Diabetes mellitus, Reproduction, Endocrine system, Insulin, Testosterone