Abstract： Objective To explore the role of H19 imprinting in etiology of pre-eclampsia. Methods Placentas of 24 women with pre-eclampsia (3 with mild pre-eclampsia and 21 with severe pre-eclampsia) and 50 healthy pregnant women at full term (control) were collected during selected cesarean delivery between August 2007 and March 2008. The statuses of H19 imprinting with placental tissues from normal pregnancy and patients with pre-eclampsia were identified upon polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The systolic and diastolic pressure were analyzed in H19 heterozygotic women. Results (1) There were 20 (40%) heterozygotes in 50 cases placenta tissues of the third trimesters, 11 (45%) heterozygotes in 24 cases placenta tissues of pre-eclampsia, There were no significant difference between two groups ( P > 0.05 ). (2) All 20 heterozygotes in placenta tissues of the third trimesters are exclusively monoallelically expressed, while 5 cases (45%) in 11 heterozygotes of pre-eclampsia are biallelically expressed (loss of imprinting, LOI). There were significant difference between two groups (P < 0. 01 ). (3) The values of systolic and diastolic pressure of patients with monoallelic expression of H19 were (171 ±9) mm Hg (1 nun Hg =0.133 kPa) and ( 104±8) mm Hg, the values of systolic and diastolic pressure with biallelic expression were ( 194±21 ) mm Hg and ( 124±18) mm Hg. There were significant difference between two groups (P<0.05 ). Conclusion LOI of H19 can be identified in pre-eclamptic placentas and is associated with maternal blood pressures, which implies the involvement of H19 gene LOI in the pathogenesis of pre-eclampsia and its potential relationship with the severity of the disease.