1) The gastric secretion following the administration of adrenocortical hormones and adrenocorticotropin (ACTH) was examined by the pylorus-ligated rats. 2) The duration of tho pyloric ligature was limited within ten hours, during which the Shay ulcer was commonly not formed and relatively pure gastric juice used to be acquired. 3) The administration of cortisone, pednisolone or desoxycorticosterone depressed the hydrochloric acid secretion, and the degree of decrease was proportional to the administration days (i.e. 1 to 46 days) and dosage (1 to 10 mg) of the hormone. But the continuous administration of 0.5 mg cortisone increased slightly the gastric secretion. 4) ACTH, which was administered subcutaneously 1 to 5 I.U. daily, stimulated highly the production of hydrochloric acid. 5) The dosage of adrenocortical hormone and the decrease in weight of adrenal glands were proportional. The atrophy of adrenals seemed to correspond to the hypacidity. This result indicates that the humoral stimulating mechanism for the gastric secretion by way of the pituitary adrenal axis is present.