Abstract: ［Abstract］Objective　To observe the effect of Dezocine in preventing the adverse reactions during the operation of cesarean delivery. Methods We selected 60 pregnant women in the ASA levelⅠwho were going to undergo the operation of cesarean delivery. Then we divided them into two groups in random: group A （studying group） and group B（ control group）， each group had 30 patients. After the fetus were delivered， the patients in group A were given intravenous injection of 1mg of dezocine， and the patients in group B were only given 1 ml saline. Then we observe the heart rate（HR），systolic blood pressure（SBP） and the degree of blood oxygen saturation （SpO2） in seven time points， and analyzed the incidence of contraction pains，chills，nausea and vomiting during the operation in both groups. The time points were when patients entered the operation room （T0）， the level of anesthesia was established （T1）， 5 minutes after fetus were delivered （T2）， 10 minutes after fetus were delivered （T3），15 minutes after fetus were delivered （T4）， 30 minutes after fetus were delivered （T5） and the end of operation （T6）. Results　Compared with group A， the SBP at T2， T3 and T4 were obviously higher than those in group B （P＜0.05）. And the HR increased at T2 to T6 in control group （P＜0.05） as compared with group A. The incidence of contraction pains were milder in group A than group B （P＜0.05）. In group A， the incidence of chills was13.3%， and in group B， the rate was 30%．Conclusion　Dezocine can prevent the adverse reactions during the operation of cesarean delivery.