To investigate the effects of berberine on ovarian blood supply in rats with polycystic ovarian syndrome (PCOS).Methods:A total of 30 rats were randomly divided into a model group,a test group and a positive control group.Dehydroepiandrosterone (DHEA) subcutaneous injection was used to construct PCOS rats; another 10 rats were selected as the control group by subcutaneous injection of soybean oil,all were intervented once a day for 20 d continuously.The test group and positive control group were given by gavage with berberine 80 mg/kg and rosiglitazone 3 mg/kg respectively.The model group and control group were given 10 mL/kg normal saline by gavage,all were given once a day for consecutive 22 d.The content of testosterone (T) and free testosterone (FT) in serum of rats were detected.Hematoxylin-eosin (HE) staining was used to observe rat ovarian tissue morphology and microvessel density (MVD).In situ hybridization and immunohistochemistry were used to detect vascular endothelial growth factor (VEGF) mRNA levels,producing rapid regulatory protein (StAR) protein expression with steroids.Results:The expression of MVD and VEGF mRNA and the relative expression of StAR protein in the ovarian tissue of the model group were higher than those of the control group,and the test group and the positive control group were lower than the model group.The experimental group was lower than the positive control group (P<0.05).Conclusion:Berberine can improve ovarian morphology by regulating blood supply and angiogenesis in ovarian tissues of PCOS rats; and can improves hyperandrogenism by down-regulating the expression of StAR protein.