Normal and pathological antral mucosa (gastric ulcer, gastroduodenal ulcer, duodenal ulcer, gastric cancer, giant rugae, gastritis chronica and gastric polyp) were examined histochemically and electron microscopically. 1) It was clarified that the Ec-cells are observed only in the mucosa with intestinal metaplasia, and never in the normal mucosa. We tentatively classified the Ec-cells into two types; Ec-Ⅰ-cell and Ec-Ⅱ-cell. The specific granules in the Ec-Ⅰ-cells are polymorphous and contain a dense core enclosed by a limiting membrane which fits either tightly or loosely. The Ec-Ⅱ-cells have electron dense and polymorphous granules but do not contain a dense core in the limiting membrane. The ratio of Ec-Ⅰ-cells to Ec-Ⅱ-cells in the antral mucosa with intestinal metaplasia seems to be almost equal in gastric ulcer but smaller in gastric cancer. 2) Cell type Ⅳ-cell in the normal antral mucosa has three kinds of granules; electron dense granules (100-200 mμ in diameter), granules (about 400 mμ in diameter) which have cloud-like or bubble-like substances in the limiting membrane, and granules which are empty-looking in the limiting membrane. In gastric ulcer cases, the Ⅳ-type cells were apt to be granulated but there were no increse in the number. On the contrary, in atrophic gastritis, the Ⅳ-type cells had low electron dense granules which were empty-looking in the limiting membrane.