Abstract： Objective： To observe the clinical effect of injection of leonurus japonicus combined with carboprost tromethamine which high-risk parturients undergoing cesarean section selected. Methods：A total of 80 cases of high-risk parturients undergoing cesarean section were randomly divided into the observation group and the control group，40 cases in each group. The control group was given oxytocin injection and carboprost tromethamine， and the observation group was additionally given injection of leonurus japonicus based on the treatment of the control group. The bleeding volume during surgery and at the 2nd and 24th hours after delivery was compared between the two groups；the duration of uterine contraction and lochia，and the descending speed of fundus of uterus after cesarean section were compared between the two groups； the differences of the levels of D- dimer and fibrinogen(FIB) during delivery and on the 3rd day after delivery were compared between the two groups；the incidence of adverse reactions was compared between the two groups. Results：There was no significant difference being found in the comparison of the bleeding volume during surgery between the two groups(P＞0.05). The bleeding volume at the 2nd and 24th hours after delivery in the observation group was less than that in the control group， the difference being significant(P＜0.05). After delivery， the duration of uterine contraction in the observation group was longer than that in the control group，the duration of lochia shorter，and the descending speed of fundus of uterus faster， the difference being significant(P＜0.05). There was no significant difference being found in the comparison of the levels of D- dimer and FIB during delivery between the two groups(P＞0.05). On the 3rd day after delivery，the D- dimer level in the observation group was lower than that in the control group，and the FIB level was higher，the difference being significant(P＜ 0.05). The incidence of adverse reactions was 17.50% in the observation group and 22.50% in the control group，and there was no significant difference being found in the comparison of the incidence between the two groups(P＞0.05). Conclusion： The therapy of injection of leonurus japonicus combined with carboprost tromethamine can significantly improve postpartum hemorrhage in high- risk parturients undergoing cesarean section， and strengthen uterine contraction ability， with definite hemostatic effect and high safety.