Systolic pressure(SBP) and diastolic blood pressure(DBP), heart rate(HR) were recorded at four time points: before anesthesia(T0), infused 10 min(T1), at the delivery of the baby(T2), at the end of the operation(T3). Ramsay sedation scales were evaluated at three time points: before anesthesia (T0), skin incision (T1) and 10min after delivery (T2). (Ramsay standard for evaluation: 1 point: anxious or restless or both; 2 point: cooperative, orientated and tranquil; 3 point: responding to commands; 4 point: brisk response to stimulus; 5 point: sluggish response to stimulus; 6 point: no response to stimulus. The Apgar scores were evaluated at 1 and 5 minute after the delivery. The urinary volume, the bleeding volume and the infusion volume during the operation were measured. Adverse effects such as nausea and vomiting in 24 hour after the operation were recorded. Postoperative analgesic formula: 12mg butorphanol tartrate, 9mg granisetron hydrochloride, diluted with normal saline to 100ml. Background dose: 2 milliliter per hour, patient controlled analgesia (PCA): 0.5 milliliter, locking time:15 minutes.