Abstract： Objective　To study the role of vascular endothelial growth factor in the genesis of pregnancy induced hypertension (PIH) and its relationship with nitric oxide. Methods　Serum vascular endothelial growth factor(VEGF) levels in 41women with PIH and 20 normal pregnant women were measured by enzyme linked immunosorbent assay. The concentrations of nitric oxide (NO) in placental tissues were assayed by nitrite reductase. Results (1) Serum levels of vascular endothelial growth factor VEGF in PIH group were significantly lower than those in normal pregnancy. There was no difference between the mild PIH and normal group in the concentrations of VEGF. VEGF levels in moderate (23.1±4.1) ng/L and severe PIH (14.8±3.9) ng/L were significantly lower than those in normal group (P<0.01). (2) The concentrations of NO in placental tissues in PIH group were significantly lower than those in normal pregnancy (P<0.01). There was no difference between the concentrations of NO in mild PIH and those in normal pregnancy (P>0.05). NO levels in moderate PIH (9.1±2.1) μmol/g and severe PIH (5.6±1.8) μmol/g were significantly lower than those in control group. (3) The serum levels of VEGF positively correlated with the cocentrations of NO in placental tissues. (r=0.65, P<0.01). Conclusion　The serum levels of VEGF and the concentrations of NO in women with PIH are both suppressed. The changes of VEGF levels might play an important role in the pathogenesis of PIH.