Abstract: Objective: To analyze the clinical effects of the different uses of oxytocin in preventing the postpartum hemorrhage in cesarean section.Methods: One hundred and fifty puerpera scheduled by cesarean section were divided into the A,B and C groups(50 cases each group)by random number table method.The group A was injected with 20 U oxytocin in myometrium,the group B was intravenously injected with 10 U oxytocin after injecting 10 U oxytocin into myometrium,and the group C was injected with 5 U oxytocin by Murphy's tube combined with intravenous injection with 10 U oxytocin.The placental separation time,blood loss during operation and after 24 hours of operation,adverse effect,blood pressure and heart rate in three groups were observed.Results: The mean blood loss during and after 24 h of operation,and placental separation time in group C were(244.1±26.1)mL,(87.4±13.9) mL and(1.6±0.4)min,respectively,which was less than that in group A and group B(P<0.01).The mean arterial pressure in three groups after 5 min of admission decreased compared with before admission(P<0.01),and began to increase after 10 min of admission(P<0.01).The heart rates in A,B and C groups after 10 min of admission gradually decreased in turn(P<0.05 to P<0.01).The differences of the incidence rates of adverse reaction between three groups were not statistically significant(P>0.05).Conclusions: The 5 U oxytocin injecting by Murphy's tube combined with intravenous injection with 10 U oxytocin can effectively reduce the blood loss and placental separation time,which has little effect on the blood pressure and heart rate,and is worthy of promotion.