CS476 has no hypoglycaemic effect in totally pancreatectomized dogs nor in streptozotocin diabetic dogs and rats. The maximal hypoglycaemia produced by intravenous administration of CS476 is comparable on a weight basis to that produced by Glibenclamide, in normal fasting dogs, rabbits, rats and mice. Randomized Latin square experiments in dogs show that CS476(0.03 mg/kg; p.o. ) and of Glibenclamide cause the same maximal decrease of blood glucose and that CS476 has the shorter duration of action. The insulin releasing activity is studied in dogs after intravenous and oral administration of equipotent doses of CS476, Tolbutamide and Glibenclamide[1].