Serum levels of leptin, insulin like growth factor (IGF)Ⅰ, IGF binding protein 1(IGFBP1), fasting insulin (FINS) were determined in 36 patients with polycystic ovary syndrome (PCOS) and 26 control subjects. The results showed that serum leptin, IGF Ⅰ, FINS in PCOS patients were significantly higher than those in control subjects, and serum IGFBP1 level was significantly lower than that in control subjects. Serum leptin was positively correlated with FINS in PCOS patients.