Total pancreatectomy was performed in dogs; and arginine test was conducted at the first, second and third weeks after surgery, and measurement was made of blood glucose, glucagon and insulin on a time-course basis for a comparative study with normal dogs. 1) After total pancreatectomy, glucagon reacting to 30 K antibody decreased once but increased with the lapse of time when no insulin was administered. 2) In the arginine test, glucagon showed a biphasic reaction in normal dogs, but a monophasic reaction in totally depancreatized dogs. This reaction declined three weeks after surgery. 3) When blood samples were taken from the pancreaticoduodenal vein, the left-gastroepiploic and mesenteric veins, during and after arginine was infused for 30 minutes. Glucagon in the pancreaticoduodenal vein increased markedly, but there were no such prominent changes in the left-gastroepiploic or mesenteric veins, Meanwhile, the level of glucagon in the left-gastroepiploic vein increased remarkably in dogs one week after total pancreatectomy.