Abstract: Objective To explore the value of enoxaparin in preventing preeclampsia in high-risk pregnant women. Methods A prospective cohort study was performed in pregnant women with high risk factors associated with preeclampsia from June 2016 to June 2018 in the Affiliated Hospital of Yan'an University. All patients were assigned into two groups according to the preventive treatment method. The observation group(n=101) received enoxaparin plus aspirin, while the control group(n=104) received aspirin alone. The incidence of preeclampsia and pregnancy outcomes were compared between the two groups. Results The incidence of severe preeclampsia in the observation group was lower than that in the control group 36 cases(35.6%) vs 45 cases(43.3%), P=0.034, and the initiation of preeclampsia treatment was later (31.9±4.3) weeks vs(30.6±4.7) weeks, P=0.040. There was no significant difference in the incidence of preeclampsia between the two groups(P=0.264). Compared with the control group, the premature delivery rate of the observation group was lower 24 cases(23.8%) vs 41 cases(39.4%), P=0.016, while the incidence of adverse reactions was higher 13 cases(12.9%) vs 4 cases(3.8%), P=0.019. There was no significant difference in the time of pregnancy termination, the incidence of fetal growth restriction and placental abruption between the two groups(all P > 0.05). In the observation group, the NICU transfer rate was less than that in the control group 18 cases(17.8%) vs 33 cases(31.7%), P=0.021. Conclusion Compared with use of aspirin alone, enoxaparin plus aspirin can effectively reduce the incidence of severe preeclampsia, delay the intervention, decrease the preterm birth, and reduce the rate of NICU transfer.