Adherence of erythrocytes of patients with transient ischemic attack(TIA) to human umbilical vein endothelial cells(HUVEC) treated with H2O2 were quantitatively studied in the flow chamber system. The results showed that injured HUVECs enhanced the adherence of erythrocytes to endothelial cells in patients with TIA. The increased adhesion of erythrocytes to endothelial cells might promote the vascular damage. Consequently endothelium might play an important role in the increased adhesiveness of TIA RBC to endothelial cells.