Aim The changes of the levels of blood sugar and plasma insulin in obese woman pa-tients with insulin resistance and the effect of insulin intravenous infusion during oper-ation were observed. Methods 10 patients of normal weight(contrast group, group A)and 20 patients of obesity women(ASA grade Ⅰ- Ⅱ) undergoing selective surgerywere investigated. The patients of obesity were randomly divided into two groups(group B and C, respectively). Groups A and B liquids without glucose, and in group Ctransfuse liquids with glucose and insulin(4g glucose add 1U insulin) were transfusedduring operation. The levels of blood sugar and plasma insulin were measured beforeand after anesthesia, during operation(30min) and after operation respectively. ResultsThere was an insulin resistance phenomenon in patients with obesity. The levels ofblood sugar and plasma insulin in patients with obesity were remarkably higher thanthose in patients of normal weight. The levels of blood sugar and plasma insulin wereextremely raised after anesthesia and during operation. The levles of blood sugar wasinhibited as insulin was infused during operation, but no hypoglycemic reaction wasfound. Conclusion There are insulin resistance phenomenon in patients with obesity.Insulin infused during operation can prevent blood sugar rise and minimize glucosemetabolism turbulence.