Objective:To explore the clinical value of shear wave elastography(SWE) in quantitative evaluating placental elasticity with preeclampsia. Methods:The hemodynamics of umbilical artery and bilateral uterine artery (S/D, PI, RI) were measured routinely in 76 singleton pregnant women (22 preeclampsia cases in group A and 54 cases in healthy group B).The modulus of elasticity in four different regions of placenta,incuding central fetal surface,central maternal surface,marginal fetal surface and marginal maternal surface,were measured by SWE.Then,the ROC curve was drawn according to the average modulus of elasticity in the four regions of the placenta to obtain the best critical value for the diagnosis of preeclampsia then, its sensitivity, specificity, positive predictive value and negative predictive value were calculated. Results:In the group A, The modulus of elasticity of the central fetal surface, the central maternal surface, the marginal fetal surface and the marginal maternal surface in group A and group B were 8.54 ±3.74KPa, 9.46±3.64KPa, 8.48±2.66KPa and 9.25±3.00KPa and 6.38±1.87KPa, 6.51±1.52KPa, 6.37±1.55KPaand 6.48±1.58KParespectively.The modulus of elasticity of group A were higher than group B(P < 0.05). The difference in the elasticity of four regions between the two groups had no statistically difference (P > 0.05).The area under the ROC curve for predicting preeclampsia by the mean value of placental elasticity was 0.754 and the threshold value was 8.19 KPa. The sensitivity, specificity, positive predictive value and negative predictive value were 64%, 96%, 88%, 87%, respectively, and the coincidence rate was 87%. Moreover,placental elasticity was significantly correlated with hemodynamics paremeters of uterine arteries (P < 0.05), but insignificantly withthat of umbilical arteries (P > 0.05). Conclusion:The modulus of elasticity of placental in preeclampsia is higher than that of normal pregnancies.SWE can quantitatively obtain the placental tissue stiffness, which can help evaluate the placental function of pregnant women with preeclampsia