Abstract: Polycystic ovary syndrome（PCOS） is the most common reproductive endocrine disorders，affecting those women of childbearing age，but its pathogenic factors is unknown so far. PCOS has a high degree of familial aggregation，indicating genetic factors play an important role in the pathogenesis. Plasminogen activator inhibitor-1（PAI-1）is the main physiological inhibitor of fibrinolytic system，and a large number of studies have shown that 4G/5G polymorphism in promoter region of PAI-1 gene can effect insulin sensitivity by elevating the level and activity of plasma PAI-1，involved in the formation of insulin resistance (IR). IR is the mainly pathophysiology of PCOS，closely related to obesity and spontaneous abortion of PCOS，prompting that PAI-1 gene 4G/5G polymorphism may have a close relationship with the occurrence and development of PCOS. Therefore,the related research about 4G/5G polymorphism in promoter region of PAI-1 gene and PCOS has become a hot spot in recent years, mainly involved the pathogenesis，obesity，IR，spontaneous abortion and the forward complicated with cardiovascular disease of PCOS，but the conclusion is still controversial.

Key words: Polycystic ovary syndrome, Plasminogen activator inhibitor 1, Insulin resistance, Polymorphism, genetic