Abstract: Objective: To explore the maternal and neonatal outcomes in the early-onset severe preeclampsia for providing the reference in clinic.Methods: The clinical data of 107 patients with severe preeclampsia were retrospectively analyzed,and the patients were divided into the early-onset severe preeclampsia(35 cases,group A with pregnancy ≤33⁺⁶ weeks,) and late-onset severe preeclampsia(72 cases,group B with pregnancy ≥34 weeks) according to the onset gestational week.The general condition,complication,delivery mode and perineonate outcome were observed in two groups.Results: The incidence rates of preeclampsia,preeclampsia complicated with thyroid disease or abnormal glucose metabolism in group A were significantly higher than those in group B(P<0.01).The incidence rates of abnormal renal function and liver function in group A(45.7% and 42.9%) were obviously higher than those in group B(9.7% and 5.6%),respectively(P<0.01).There were not statistical difference in the incidence rates of HELLP syndrome,eclampsia,abruptio placentae,cardiac failure and anemia in group B(P>0.05).The incidence rates of fetal growth restriction and mortality of perineonates in group B were less than that in group A(P<0.01 and P<0.05).Conclusions: There is high frequency of maternal and neonatal complications in patients with the early-onset severe preeclampsia,and the short-term expectant treatment can be implemented before the termination of pregnancy.The active treatment can significantly improve the maternal and neonatal outcomes,but the maternal and neonatal condition should be closely monitored,and the pregnancy should be timely terminated during the expectant treatment.