Objective To observe the analgesia effect of continuous epidural block anesthesia with different concentrations of sulfentanyl combined with ropivacaine for labor,so as to explore the suitable concentration of sulfentanyl for labor analgesia.Methods Totally 120 full term pregnant women,American Society of Anesthesiologists (ASA) Ⅰ-Ⅱ level,aged 22-36 years old,were evenly randomized into 4 groups according to the concentrations of sufentanil.Continuous epidural block anesthesia was performed for all participants:group A:0.1% pure ropivacaine,group B:sufentanil 0.2 μg/mL+0.1% ropivacaine,group C:sufentanil 0.4 μg/mL+0.1% ropivacaine,and group D:sufentanil 0.6 μg/mL+0.1% ropivacaine.The VAS scores were recorded before and 10,20,and 30 mins after analgesia.The labor process,postpartum blood loss and neonatal Apgar score were also observed.Results The VAS scores were similar in the four groups before analgesia.The VAS scores of group C,D were significantly lower than that of group A at both 10 mins and 20 mins after analgesia (all P0.05).At 20 mins after analgesia,the VAS scores of group D was significantly lower than those of group B and C (both P0.05).The incidence rates of urine detention and inching were significantly higher than those of the other three groups (all P0.05).Conclusion Sulfentanyl combined with ropivacaine can achieve better outcome than ropivacaine alone for continuous epidural block anesthesia of labor,with 0.4 μg/mL sufentanil+0.1% ropivacaine having the best effect and less adverse effects.It has no effect on the first,second stages of labor,postpartum blood loss or neonatal Apgar score.(Shanghai Med J,2012,35:1035-1038)