1. Effects of alloxan-induced diabetes on the rat gastric acid secretion were investigated using a number of biostatistical models described earlier. 2. Histamine-induced gastric acid secretion was found to be decreased in alloxan-diabetic rats when compared with their age-matched controls. 3. Basal acid secretion was also decreased depending on experimentally-induced diabetes. 4. The above results strongly suggest that alloxan-induced diabetes depresses vagal activity and H2-receptor activity in the stomach.