Background Preeclampsia,characterized by hypertension and proteinuria,is a multifactorial disease associated with shallow invasion of trophoblast cells and inadequate spiral artery remodeling.Trophoblast and tumor cells have similar invasion mechanism.Prostasin is closely related to tumor development,invasion and metastasis and influences blood pressure through activating epithelial sodium channel.The effect of prostasin on the pathogenesis of preeclampsia remains unclear.This study investigated the association of prostasin gene at rs12597511 with severe preeclampsia.Methods A single nucleotide polymorphism,rs12597511,was tested with polymerase chain reaction and restrictionfragment length polymorphism analyses in 179 severe preeclampsia patients and 222 normal pregnant women.Results The frequencies of TC + CC genotypes were significantly higher in severe preeclampsia group compared with in control group (the adjusted odds ratio was 2.030,95％ confidence interval 1.195-3.449,P=0.009).The C allele of rs12597511 was present significantly more often among women with severe preeclampsia (P=0.001).Genotyping analysis showed that the C allele of rs12597511 could confer a risk for severe preeclampsia.Conclusion The higher frequency of C allele of prostasin gene at rs12597511 is associated with severe preeclampsia.