PURPOSE: This research was conducted to provide basic information about the effects of aerobic exercise on physiological change in middle-aged obese women according to differences of beta3-adrenergic receptor polymorphisms. METHOD: Twenty-nine middle aged obese women with over 30%BMI were divided into three groups according to beta3-adrenergic receptor gene polymorphism[Variable Group(VG):9, Normal Group(NG):10, Control Group(CG):10]. The VG and NG groups performed walking at 50% exercise intensity for 30 minutes a day, 4 days a week, for 12 weeks. The data was analyzed using the SPSS program. RESULT: The level of leptin, insulin and % body fat in the VG and NG groups was significantly lower than those of the CG after 12 weeks. In addition, the level of HDL-C in the VG and NG was significantly higher than that of the CG after 12 weeks. However, TC, TG and body weight between groups didn't appear significant at the end of 12 weeks. CONCLUSIONS: Aerobic exercise didn't cause differences in persons with differing beta3-adrenergic receptor gene polymorphisms, but aerobic exercise affected the physiological change in middle-aged obese women. The findings suggest that aerobic exercise is a desirable nursing intervention for obesity control in middle-aged obese women.