The purpose of this study is to analyze the effects of aerobic exercise on immune function, physical fitness and fat mass in middle-aged women. Twenty subjects were divided into two groups : experimental group(N:10) and control group(N:10). Experimental subjects were under the exercise conditions to perform the aerobic exercise using the movement of dance-sports with intensity of 60~80% HRmax for 60 min/day, 3 times/week during 12 weeks. After the aerobic exercise, the numbers of neutrophil, Iymphocyte, eosinophil, basophil, 73, 74 and B4 were significantly different. Crip-strength and sit-up ability significantly improved and all so weight and fat mass decreased on experimental group. Therefore, the aerobic exercise using the movement of dance-sports applying to middle-aged women would contribute them healthy life and prevention of chronic disease.