The fine distributions of the blood vessels can be readily and clearly demonstrated by preparing their solid corrosion casts and by observing the corrosions thus obtained under the scanning electron microscope. As examples, the scanning electron micrographs of the capillary meshes of the rat's renal glomerulus, gastric mucosa, intestinal villi and hepatic lobules reproduced with methacrylic methyl ester resin were shown. And the procedure employed in the casting and scanning electron microscopy was described. In the casting methods, some improvements were made to reproduce delicate capillaries such as those of the villi of the small intestine.