OBJECTIVE:To observe the efficacy of Methyl Carboprost-NEGPF administered per rectum at different time in preventing postpartum hemorrhage in patients with vaginal delivery.METHODS:A total of 300 parturients undergoing vagi-nal delivery with possible postpartum hemorrhage were enrolled:Methyl Carboprost-NEGPF 1 granule(1mg) per rectum (with a suitable inserting depth of 6 cm) were administered in Group A(n=100) when their uterine orifices were fully open and Group B(n=100) after fetal delivery,while Group C(n=100) were injected i.m with oxytocin 10IU after fetal delivery. The three groups were compared in respect of third stage labor duration,postpartum blood loss amount at 2h and 24h and case numbers with postpartum hemorrhage.RESULTS:As compared with Group A and Group B,Group C was significantly different in the duration of third stage of labor and postpartum blood loss amount at 2h and 24h(P