Abstract： Objective:To investigate the expression of soluble macrophage colony-stimulating factor receptor like tyrosine kinase 1(sFlt-1)and plasma placental growth factor(PLGF)in placental tissues and their correlation with the occurrence of preeclampsia.Methods:This study was a randomized controlled study, a total of 70 cases of preeclamptic puerpera who received in the department of Obstetrics and Gynecology of the First Hospital of Yulin from June 2021 to June 2023 were selected for inclusion in the preeclamptic group, aged(28.42±4.12)years old, ranging from 22 to 45 years old, and another 70 cases of healthy puerpera with normal blood pressure who delivered in the department of Obstetrics and Gynecology of the First Hospital of Yulin during the same period of time were selected for inclusion in the healthy group, aged(27.91±3.86)years old, ranging from 21 to 43 years old.The expression levels of sFlt-1 and PLGF and placental micro vessel density(MVD)were measured in the placental tissues of the two groups, and the correlation between the expression levels of sFlt-1 and PLGF in the placental tissues of the two groups and MVD was analyzed, as well as the diagnostic efficacy of preeclampsia.Results:In the preeclamptic group, the expression level of sFlt-1 in placental tissues of puerpera with severe preeclampsia[(1.27±0.36)pg/L]was higher than that in the healthy group [(0.38±0.12)pg/L], and the expression level of PLGF[(0.69±0.20)pg/L]was lower than that in the healthy group [(1.14±0.28)pg/L]; the expression level of sFlt-1 in placental tissues of puerpera with severe preeclampsia[(1.45±0.41)pg/L]was higher than that of puerpera with mild preeclampsia [(1.01±0.29)pg/L]; the expression level of sFlt-1 in placental tissues of puerpera with severe preeclampsia [(1.45±0.41)pg/L]was higher than that of puerpera with mild preeclampsia [(1.01±0.29)pg/L], and PLGF expression level [(0.52±0.13)pg/L]was lower than that in mild preeclamptic mothers [(0.86±0.24)pg/L]; MVD in the placental tissues of preeclamptic group [(101.42±8.95)bars/high power field]was less than that in the healthy group [(138.52±14.07)bars/high power field], the differences were statistically significant( P<0.05).MVD in the placental tissues of mothers in the preeclampsia group and healthy group was negatively correlated( P<0.05)with the expression level of sFlt-1( r=-0.412, r=-0.389), and positively correlated( P<0.05)with the expression level of PLGF( r=0.451, r=0.408).The sensitivity of sFlt-1 combined with PLGF in placental tissue for the diagnosis of preeclampsia was 90.68%, the specificity was 61.75%, and the area under the curve was 0.931. Conclusions:The high expression of sFlt-1 and the low expression of PLGF in the placental tissue of maternal preeclampsia may lead to insufficient placental angiogenesis and participate in the occurrence of preeclampsia.