To explore whether Free androgen index（FAI）can be regarded as biochemically diagnostic indexes of high androgen hormone in blood of patients with Polycentric ovary syndrome（PCOS）. Also to explore whether Sex hormone-binding globulin（SHBG） and FAI can be seen as therapeutic effect indicatrixes of women with PCOS.

Inclusion Criteria:

• The clinical diagnosis criteria for PCOS by European Society of Human Reproduction and Embryology, and Rotterdam working group of American Society for Reproductive Medicine (ESHRE /ASRM )

Exclusion Criteria:

• hyperprolactinemia and other endocrine diseases such as high androgen hormone in blood, namely Cushing's syndrome, congenital adrenal hyperplasia ( CAH ), ovarian or adrenal tumor and so on

The investigators collected 534 PCOS patients as the case group, 580 infertile women with normally ovulatory cycle as the control groupand.The patients of the case group aged from 20 to 42 years old, the average age was 27.87 years old, and the standard deviation of ages was 3.75 years old. And patients' ovulation in the case group was normal, as control group, aged from 20 to 43 years old, the average age was 28.18 years old; the standard deviation of ages was 3.99 years old.Also the investigators also collected 579 patients as the treatment group,who aged from 20 to 39 years, the average age was 27.93 years old, the standard deviation of ages was 3.70 years old.