Correlation between advance of age and changes of basal lamina width of mucosal epithelium and capillary was estimated in both the fundic gland and the pyloric gland, respectively, by electron-microscopic morphometry, using C57BL/6N mice. In basal lamina width of mucosal epithelium, no change was found in both the glands throughout life. In basal lamina width of mucosal capillary, change related to aging was not found in the fundic gland, but in the pyloric gland; it increased in the old mice. This fact is considered to be related to physiological and anatomical differences of microcirculation between the two glands.