E-selectin is an endothelial lectin that plays a critical role in tethering of leukocytes or hematopoietic progenitors to endothelial cells (ECs). Here we studied the role of E-selectin in endothelial progenitor cell (EPC) homing and new vessel formation. After ischemia, the expression of E-selectin on ECs peaked 6-12 h and returned to baseline at 24 h whereas the level of soluble E-selectin (sE-selectin) in serum increased over 24 h and remained high at day 7. Mouse bone marrow-derived EPCs expressed not only E-selectin but also its ligand. E-selectin knock-out mice, as well as wild type mice pretreated with blocking antibody against E-selectin, showed impairment in circulating EPCs��� homing to ischemic limb, which was rescued by local sE-selectin injection. Mechanism for this is that sE-selectin stimulated not only ECs to express ICAM-1, but also EPCs to secrete IL-8, leading to enhanced migration, tube formation, and incorporation to EC���s capillary formation. In therapeutic aspect, local treatment with sE-selectin enhanced the efficacy of EPC transplantation for vasculogenesis and salvage of ischemic limb. Conversely, when E-selectin was knocked-down in ischemic limb by systemic administration of E-selectin small interfering RNA (siRNA), blood flow recovery after EPC transplantation was significantly impaired. But this impaired vasculogenesis in ischemic limb was rescued by local injection of sE-selectin. In conclusion, these data clearly demonstrate E-selectin is a pivotal molecule for EPCs��� homing to ischemic limb and vasculogenesis.