To investigate the effect of ginsenoside Rg1 on the migration, adhesion, proliferation, and VEGF expression of endothelial progenitor cells (EPCs).EPCs were isolated from human peripheral blood and incubated with different concentrations of ginsenoside Rg1 (0.1, 0.5, 1.0, and 5.0 micromol/L) and vehicle controls. EPC migration was detected with a modified Boyden chamber assay. EPC adhesion was determined by counting adherent cells on fibronectin-coated culture dishes. EPC proliferation was analyzed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In vitro vasculogenesis was assayed using an in vitro vasculogenesis detection kit. A VEGF-ELISA kit was used to measure the amount of VEGF protein in the cell culture medium.Ginsenoside Rg1 promoted EPC adhesion, proliferation, migration and in vitro vasculogenesis in a dose- and time-dependent manner. Cell cycle analysis showed that 5.0 micromol/L of ginsenoside Rg1 significantly increased the EPC proliferative phase (S phase) and decreased the resting phase (G(0)/G(1) phase). Ginsenoside Rg1 increased vascular endothelial growth factor production.The results indicate that ginsenoside Rg1 promotes proliferation, migration, adhesion and in vitro vasculogenesis.