Objective：To explore the role of the Notch signaling members Notch1 in the mechanism of human pre-eclampsia. Methods：Placental tissues of normal pregnancy and pre-eclampsia were obtained respectively. Real-time PCR

Western blot and immunohisto－chemical method were used to detect the distribution and expression levels of Notch1 mRNA and Notch1 protein in both placental tissues. Results：Notch1 was expressed in both placental tissues and expression was localized in the membrane. Expression levels of Notch1 in placental tissues of pre-eclampsia（experiment group） were significantly lower than those in placental tissues of normal pregnancy（control group）（P<0.05）. Conclusions：Notch1 may mediate the occurrence and development of placental vasculogenesis and influence the endovascular invasion of embryonic cytotrophoblasts through the Notch signaling pathway and the reduced expres－sion level of Notch1 may be associated with the occurrence of pre-eclampsia.