OBJECTIVE： To compare the efficacy and safety of ethinyl estradiol cyproterone respectively combined with metformin and pioglitazone in the treatment of polycystic ovary syndrome. METHODS：  80 patients with polycystic ovary syndrome were randomly divided into group A （40 cases） and group B （40 cases）. All patients received 1 Ethinyl estradiol cyproterone tablet from the 5 d of menstruation， once a day， 21-d was a treatment course， then began the next course from the 5 d of the next menstruation. Based on it， group A received Metformin tablet 0.5 g， orally， 3 times a day； group B received Pioglitazone tablet 15 mg， orally， once a day. All patients were treated for 3 months. Body mass index （BMI） level， luteinizing hormone （LH）， testosterone （T）， fasting insulin （FINS）， steady state insulin evaluation index （HOMA-IR）， triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C） in 2 groups before and after treatment were observed， spontaneous ovulation rate， pregnancy rate and the incidence of adverse reactions in 2 groups were recorded after 6-month follow-up. RESULTS： There were no significant differences in the spontaneous ovulation rate， pregnancy rate and the incidence of adverse reactions in 2 groups （P＞0.05）. Before treatment， there were no significant differences in the BMI， LH， T， FINS， HOMA-IR， TG， TC， LDL-C and HDL-C levels in 2 groups （P＞0.05）. After treatment， BMI level in 2 groups was significantly lower than before， and group A was lower than group B， HDL-C level was significantly higher than before， and group B was higher than group A， with statistical significances （P＜0.05）， LH， T， FINS and HOMA-IR levels in 2 groups were significantly lower than before， with statistical significances （P＜0.05）， while there were no significant differences between 2 groups （P＞0.05）. And there was no significant difference in the TG， TC and LDL-C in 2 groups before and after treatment （P＞0.05）. CONCLUSIONS： Ethinyl estradiol cyproterone combined with metformin shows similar efficacy and safety etothinyl estradiol cyproterone combined with pioglitazone in the treatment of polycystic ovary syndrome， while metformin is obvious in reducing patients’ BMI levels， and pioglitazone is obvious in improving HDL-C levels.