Abstract: Objective: To compare the inhibiting effect of intrathecal（IT） fentanyl and intravenous （IV） ondansetron on intraoperative nausea and vomiting during cesarean delivery under epidural anesthesia. Methods: 45 healthy parturients（ASA grade to） were randomly assigned in equal numbers into controlled,fentanyl and ondansetron groups(n=15each,seperatly,parturients in the controlled group treated with IT saline 3ml,parturients in the fentanyl group treated with IT fentanyl 15μg.3ml^-1,parturients in the ondansetron group treated with IV ondansetron 4mg).The incidence of nausea and vomiting during cesarean delivery under epidural anesthesia among the 3 groups were compared and the neonate’ Apgar scorces were assessed after delivery.（Results: ）Introperative nausea and vomiting/retching were reduced in the fentanyl group and ondansetron group as compared with the controlled group（6.7% vs 13.3% vs 33.3%,P＞0.05;0% vs 0% vs 26.7%,P＜0.05）. The neonate’ Apgar scorces were not significantly different among the 3 groups（P＞0.05）.Conclusion: IT fentanyl and IV ondansetron can decrease introperative vomiting during cesarean delivery performed under epidural anesthesia.The effect of both are not different.