Background: Vascular endothelial dysfunction is the closely related determinant of ischemic heart disease (IHD).Endothelial dysfunction and ischemia/reperfusion injury (IRI) have been associated with an increase in microvesicles (MVs) in vivo.However, the potential contribution of endothelial microvesicles (EMVs) to myocardial damage is unclear.Here we aimed to investigate the role of EMVs derived from hypoxia/reoxygenation (H/R)-treated human umbilical vein endothelial cells (HUVECs) on cultured H9c2 cardiomyocytes.Results:H/R injury model was established to induce HUVECs to release H/R-EMVs.The H/R-EMVs from HUVECs were isolated from the conditioned culture medium and characterized.