Objectives: Hypertensive disorders occur in approximately 12% to 22% of pregnancies and cause substantial perinatal morbidity and mortality of both mother and fetus. Hypertensive disease is directly responsible for approximately 20% of maternal deaths and can be classified as chronic hypertension, gestational hypertension, preeclampsia-eclampsia, and chronic hypertension with superimposed preeclampsia. At present, the pathogenesis of preeclampsia is still unclear, we wrote this article to make a uptodate review of this disease. Mechanism: A comprehensive search of several databases was conducted from inception up to March 2022. The searched databases were Web of Science, MEDLINE,Ovid, and Cochrane Database of Systematic Reviews. The search strategy included the combinations of the following medical terms: Hypertensive disorders; preeclampsia; mechanism; pathogenesis hypothesis. Findings in Brief: At present,the pathogenesis of preeclampsia is still unclear, the theory of Genetic,Inflammatory Response, Immune Imbalance in Maternal-Fetal Interface, Oxidative Stress, Vascular Endothelial Cell Damage are supposed involved in the progress of preeclampsia. Conclusions: Although there are various theories mentioned above, none of the hypothesis can fully explain preeclampsia. More research is needed on the mechanism of preeclampsia.