Aim To furnish evidence of the protective barrier formed by the edge-flowing blood in vessels within cerebral cortex. Methods The corrosion casts of the microvasculature of cerebral cortex were studied by scanning electron microscopy on ten dead China children’s heads perfused with methylemthacrylate to discover the shape of endothelium of the microvessel within cerebral cortex. The characteristics of microvessel cerebral cortex were studied with microscope on 18 sides children’s cerebral hemisphere perfused with the mixture liquid of formaldehyde (formalin) and carbon black ink,the proportion was 1:6. Confocal laser scanning microscopy was used in a rabbit opening cranial window preparation in order to study optical section on the microcirculation within the cerebral cortex in vivo. The plasma was labeled by fluorescein in capillaries was visualized up to 300 μm beneath the rabbit brain surface in noninvasive optical sections. The diameter of capillaries and the thickness of edge-flowing blood in vessels were measured. The gray scale display of axial blood flow and edge-blood flow in varying vessels was measured by image analytical system, and drew a curve of gray scale display. The normal microcirculation within cerebral cortex of rabbit, the microcirculation within cerebral cortex of normal rabbit treated with the Ligustrazine (or Tetramethylpyrazine) for moving the vessel, the microcirculation within cerebral cortex of shock rabbit treated with the Ligustrazine for moving the vessel was studied by Confocal laser scanning microscopy in vivid. Results There are four kinds of microvessel within the cerebral cortex, including the superficial, middle, deep cortical artery and cortical-medullar artery. The shape of endothelium of the microvessel within the cerebral cortex in children is crude, and it’s morphology is similar to the bark of poplar or willow and pine tree. The endothelium of blood vessels within cerebral cortex in human change from roughness to smoothness as the internal diameter of the blood vessels change from large to small. Under the normal state in vivid, the edge-flowing blood in vessels within cerebral cortex was stable when the diameter of capiuaries was 121.56 μm (P=0.0262) and 60.00 μm (P=0.0539) respectirely under the shock state, the edge-flowing blovd was stable when the diameter was 60.15 μm (P=0.9358) and 48.84 μm (P=0.0053) respectinely. Conclusions There is a protective barrier formed by the edge-flowing blood in vessels within cerebral cortex, which can cover and protect the endothelium of vessels within cerebral cortex, and avoid the cerebraovascular disease.