Abstract: Objective: To compare the effect of epidural block and nitrous oxide in analgesic labor.Methods: Epidural block group were injected 0.2% ropivecaine 9 ml and fentanyl compound 1 ml in to the epidurale cavum and 5 ml mixture was added according to the maternity conditions.Nitrous oxide group 50% nitrous oxide and 50% oxygen.Results: The anesthetic effect differed significantly during the active period and the second labor stage(P<0.01).The time of second labor stage in the epidural block group was longer than that in nitrous oxide group(P<0.05).There was no significant difference in the first labor stage,the third labor stage,the mode of delivery,bleeding volumn,fetal distress and neonatal asphyxia(P>0.05).There was no significant difference in the oxygen saturation and diastolic pressure after anesthesia.The nitrous oxide group had higher respairatory rate,heart rate and systolic pressure than the epidural block group(P<0.05 to P<0.01).Conclusions: The anethestic effect of epidural block is much better than that of nitrous oxcide.Patients using epidural block must be monitored by a technical analgesist and the second birth process has the to extend.The anethetic effect of nitrous oxide is a bit weak,but the patients do not need a technical analgesist.Nitrous oxide is better accepted by the patient and the hospital at the basic level. Back