Abstract： Objective To explore the optimal time for clinical interventions on full-term or nearterm pregnant women with premature rupture of membranes(PROM). Methods A retrospective study was conducted on clinical data of 903 healthy, full-term or near-term (gestational age ≥ 35 weeks), singleton pregnant women with PROM, who admitted to our hospital from January 1, 2005 to December 31, 2009. All subjects were divided into 6 groups: women in group 1 were those fell into spontaneous labor within 6 h after PROM (n=269, 29.8%); women in group 2 were in spontaneous labor between 6 to 12 h after PROM (n= 161, 17.8%) ; women in group 3 were in spontaneous labor at 12 to 24 h after PROM (n = 75, 8. 3%); In group 4 oxytocin was administered for induction for women not in labor at 6 to 12 h after PROM (n= 124, 13.7%) ; Group 5 included those women who were not in labor at 12 to 24 h after PROM and oxytocin induction was offered (n=98, 10. 9%);Group 6 consisted of those women who were not in labor over 24 h after PROM and oxytocin induction was offered (n = 176, 19. 5%). The maternal and neonatal complications and outcomes of all pregnancies were reviewed and compared. Results Among the 903 cases, the total number of women without any medical interventions was 681, among which 505 (74.2%) fell into spontaneous labor, including 430 (63.2%) within 12 h with a cesarean section rate(CSR) of 20.7%(89/430), 75 (11.0%) at 12-24 h after PROM with the CSR of 50.7% (38/75), and 176 (25.8%) did not go into labor spontaneously (group 6) with a CSR of 70. 5% (124/176). (2) Among the 930 women, 398were induced at 6, 12 and 24 h after PROM. The CSR, incidence of intrauterine infection, puerperal morbidity and perinatal mortality rate in group 5 were significantly lower than those of group 6 [CSR:52.0%(51/98) vs 70. 5%(124/176); intrauterine infection: 6. 1%(6/98) vs 22. 7%(40/176);puerperal morbidity: 6. 1% (6/98) vs 19.9% (35/176); perinatal mortality: 7. 1% (7/98) vs 20.5%(36/176),all P＜0. 01], but no difference was found in the incidence of postpartum hemorrhage [1.0%(1/98) vs 4.0%(7/176), P＞0.05]. Conclusions Intervention is not recommended within 12 h after PROM in full term or near term gravidas. However, induction of labor should be offered thereafter. However, the CSR and incidence of maternal and neonatal complications rise up if induction of labor postponed to 24 h after PROM.