Abstract： Objective To investigate the expression of integrin linked kinase (ILK) in endothelial progenitor cells (EPC) of cord blood from patients with preeclampsia and its relation to placenta perfusion. Methods Thirty patients with preeclampsia,including 18 mild preeclampsia and 12 severe preeclampsia cases,and thirty-five normal late pregnant women were enrolled into this study.The expression of ILK mRNA and protein in EPC of cord blood was determined with RT-PCR and Western blot respectively.The angiogenesis ability of EPC was examined by tube formation in vitro.Comparisons of ILK mRNA and protein expression were done by analysis of variance and their relations to vascular tube formation were analyzed by correlation analysis. Results (1) ILK mRNA expression in normal group was higher than that in preeclampsia group (0.64± 0.05 vs 0.45 ± 0.06,q=18.76,P＜0.05) and the ILK protein expression in normal group was also higher (32 ±2 vs 26±1,q=18.47,P＜0.05).While the ILK mRNA and protein expression in mild preeclampsia group were also higher than that of severe preeclampsia group (ILK mRNA:0.47±0.07 vs 0.39±0.08,q=5.13,P＜0.05;ILK protein:25±2 vs 20±2,q=4.72,P＜0.05).(2) The tube formation capacity in preeclampsia group was significantly lower than that in normal group (135± 7 vs 330 ± 8,q=152.70,P＜0.05) ; the capacity was even much lower in severe group than in mild group (116±8vs 148±6,q=5.42,P＜0.05).(3) There was positive correlation between ILK mRNA and protein expression and tube formation capacity; the correlation index for normal group was 0.69 and 0.73(P＜0.05),0.67 and 0.72 in preeclampsia group (P＜0.05),0.65 and 0.68 in mild preeclampsia group (P＜0.05) and 0.63 and 0.74 in severe preeclampsia group (P＜0.05). Conclusions Decreased ILK level of EPC in cord blood might play an important role in the development of preeclampsia.