Objective : This study was designed to investigate the effects of Angelicae Gigantis Radix (AGR) on Polycystic Ovary (PCO) induced by Estradiol valerate (EV) in female rats. Methods : We investigated the effects of AGR on Changes in body weights and food and water uptake for 5 weeks. In addition, we examined the effects on ovary weights. Finally, we also observed histopathological changes in PCO rats. Results : Treatment with AGR did not affect body weights, amount of food and water uptake. Administration group of AGR restored body/ovary weight ratio to normal levels, which were lowered by induction of PCO. In histopathological observation, formation of cysts was suppressed in AGR group compared with non-treated control group. Conclusion : These results suggest that AGR can be used for patients with PCO to prevent formation of cystic follicles and malfunction of ovary.