1. The gastric juice of the adult rats, with histamine injection, with extirpation of endocrine organ, vagotomy and fracture of femur was collected respectively for 6 to 12 hours after pylorus-ligature. The samples were studied on quantity and peptic activity. The urine was collected for 24 hours after the same procedures and studied on uropepsin. 2. As a result of histamine injection, the peptic actvity of gastric secretion was slightly depressed. The peptic activity showed moderate depression with adrenalectomy, marked depression with hypophysectomy or adreno-hypophysectomy, some depression with vagotomy or thyreoidectomy, slight change with orchiectomy or oophorectomy and slight depression with fracture. On the other hand, the uropepsin level in urine showed no remarked change with histamine injection, decrease with adrenalectomy, moderate increase with hypophysectomy when the ample water was administered; slight decrease with vagotomy, no change with thyroidectomy, slight change with orchiectomy or oophorectomy and increase with fracture. 3. From the above experiments, it was concluded that the pepsinogen secretion into gastric lumen was not always parallel with its excretion into urine. It was suggested that there is some difference between the factors influencing upon the exocrine mechanism of the pepsinogen and those upon the endocrine mechanism.