Objective: Recently, reports have indicated that the imbalance of circulating angiogenic factors is important in the onset of preeclampsia. In this study we investigated angiogenic factor levels in women with preeclampsia, preeclampsia superimposed on chronic glomerulonephritis, gestational proteinuria, and normal pregnancies. Study design: We measured several circulating angiogenic factors, placental growth factor, vascular endothelial growth factor, soluble fms-like tyrosine kinase-1, and soluble fetal liver kinase 1. Results: Compared with women with normal pregnancies, placental growth factor concentrations were lower, and soluble fms-like tyrosine kinase 1 concentrations were higher in women with preeclampsia and gestational proteinuria; soluble fms-like tyrosine kinase 1 concentrations were also higher in women with preeclampsia superimposed on chronic glomerulonephritis. Conclusion: There were obvious differences in the levels of circulating angiogenic factors placental growth factor and soluble fms-like tyrosine kinase 1 among preeclampsia, gestational proteinuria, and controls. The imbalance of angiogenic factors is important in the onset of preeclampsia superimposed on chronic glomerulonephritis. Objective: Recently, reports have indicated that the imbalance of circulating angiogenic factors is important in the onset of preeclampsia. In this study we investigated angiogenic factor levels in women with preeclampsia, preeclampsia superimposed on chronic glomerulonephritis, gestational proteinuria, and normal pregnancies. : We measured several circulating angiogenic factors, placental growth factor, vascular endothelial growth factor, soluble fms-like tyrosine kinase-1, and soluble fetal liver kinase 1. Results: Compared with women with normal pregnancies, placental growth factor concentrations were lower, and soluble fms-like tyrosine kinase 1 concentrations were higher in women with preeclampsia and gestational proteinuria; soluble fms-like tyrosine kinase 1 concentrations were also higher in women with preeclampsia superimposed on chronic glomerulonephritis. Conclusion: There were obvious differences in the levels of circulating angiogenic factors placental growth f actor and soluble fms-like tyrosine kinase 1 among preeclampsia, gestational proteinuria, and controls. The imbalance of angiogenic factors is important in the onset of preeclampsia superimposed on chronic glomerulonephritis.