The goal of this study was of what change in blood glucose the operation area and ageing made during halothane anesthesia. Sixty patients who were chosen randomly were divided into 4 operation groups according to operation site, that is, nil, surface, abdomen and thorax. Again, each operation group was fractionated into the young(below 40 year old), the middle (from 4l to 60) and the old(above 61). The blood sampling was done at preinduction for control value, 15 min, 30 min, 45 min and 60 min after induction for nil, and 15 min, 30 min, 45 min and 60 min after incision for operation-received groups. The results were as follows; 1) In nil, the young and the middle increased, but the old decreased in blood glucose. 2) In operation-received groups, there was no significance in blood glucose change among 3 age fractions. 3) The blood glucose change was larger in operation-received groups than in nil, more prominent in abdomen and thorax groups than in surface group. 4) The blood glucose of preinduction had no significance among 4 operation groups.