Abstract： Objective To silence the expression of tissue factor(TF) gene of human umbilical vein endothelial cell(HUVECs) of the newborns with placental abruption(PA) and normal newborns.Methods There were two groups in the experiment,normal group and PA group.Three different treatments were established in each group:(1) the blank; (2) the false-intervention ; (3) the TF gene silencing.There were three samples in each treatments.After these treatments,the changes of mRNA expression of the HUVECs were observed before and aftcr thc gene silencing and the changes of the immunofluorescence of the TF protein level.Results After amplificated,plasmid DNA were sequenced to show that the pENTRTM/U6-TF-shRNA was the positive clone.After the transfected,the levels of the mRNA of TF decreased from 0.657 ± 0.097 to 0.220 ± 0.030 and 1.323 ± 0.323 to 0.207 ± 0.150 in the normal and PA group respectively.Compared with the normal group,there were significant differences for the levels of TF mRNA in PA group with the blank,(1.323 ± 0.323 vs 0.657 ± 0.097,P =0.023) and the same result for the second management (1.057 ±0.178 vs 0.540 ± 0.079,P =0.01).But there was no significant difference between the normal and PA group after RNA interference gene silencing (0.220 ± 0.030 vs 0.207 ± 0.150,P ＞ 0.05).Meanwhile,there were significant differences among the three managements in the themselves groups of normal and pathological ones(F =19.30,P =0.002 ;F =27.66,P =0.001).Conclusion The vectors are transfected into HUVECs and play the biological function.And they silence the expression of TF mRNA.PENTRTM/U6-TF-shRNA could inhibit the expression of TF mRNA of HUVECs in the PA newborn.