A newly improved method for controlling blood glucose was compared with the standard model predictive controller under continuous glucose infusion. Continuous intravenous glucose infusion at rates of 50 or 100 mg/kg/hour was conducted on pancreatectomized dogs. An improved blood glucose control method using a combination of the proportional controller in the initial stage and the model predictive controller in the later stage was compared with the simple model predictive controller. The parameters of the controller were determined by identifying individual responses to the infused insulin during the first 60 minutes. The parameters of the proportional controller were changed at 60, 90, and 120 minutes to reflect the response to the infused insulin. The simple model predictive controller was able to reach the target level in the usual manner under the low infusion rate of glucose. However, under glucose infusion rates of 100 mg/kg/hour and more, it was difficult to reach the target level within 8 hours. In contrast, the improved system could reach the target level within 5 to 8 hours even under continuous glucose challenge. Addition of the modified proportional controller to the model predictive controller can stabilize the blood glucose control even under continuous glucose infusion.