Objective:To compare the safety and efficacy of sublingual administration of misoprostol with intravenous oxytocin infusion for labor induction in cases with unripe cervix and premature rupture of membranes (PROM) at term.Methods:Sixty patients were randomly divided into two groups:sublingual administration of misoprostol and continuous intravenous infusion of oxytocin.Results:Thirty subjects were allocated to the misoprostol group and thirty to the oxytocin group.The mean (±standard deviation) interval from induction to delivery was significantly shorter in the misoprostol group (7.25±4.63 h vs 18.88±15.66 h, P<0.001).The labor successful rates within 24 hours were significantly higher in the misoprostol group (90.0% vs 53.33%, P<0.005).For 70.0% of patients in the misoprostol group,one dose was reguired.Intrapartum complication rates,mode of deli-very,and neonate or maternal adverse event rates were similar in the two treatment groups.Conclusion:Sublingual administration of misoprostol induces labor safely and effectively in patients with PROM and unripe cervix at term.