This study was conducted to test the effects of participation in 12-week program of boxing aerobics by obese middle-aged women on their body composition, blood constituents, and vascular compliance The samples are the middle-aged women in their forties or more, who has 30% or more body fat percentage, but has no medical history in cardiovascular disorders or metabolic diseases. The samples are divided into 8 of exercising group, and 8 of control group by random assignment. The intensity of boxing aerobics was HRmax 50% for the initial 4 weeks, HRmax 60% for the 5th to 8th week, and HRmax 70% for the 9th to 12th week. Each session took 60 minutes. The result is as follows. First, as a result of participating in the boxing aerobics program, body weight, body fat percentage, and muscle showed significant differences depending on the measuring period and the interacting term of the group and measuring period(p<.001), and the result of t-test on the sample matched to each group's measuring time also showed the significant increase or decrease in the exercising group(p<.001). Second, as a result of participating in the boxing aerobics program, the exercising group's TC, TG, HDL-C, and LDL-C, all showed significant differences in accordance with each group, measuring time, and the interaction term between groups and measuring time(p<.01, p<.001), and the result of t-test on each group's samples matched to the measuring time also shows significant increase or decrease in the exercising group(p<.01). Third, as a result of participating in the boxing aerobics programs, the vascular compliance of right hand, left hand, right hand, and left hand showed significant differences in accordance with each group, measuring time, and the interacting term between the measuring time and the group(p<.001), the t-test results of the samples matched to the each group's measuring time also showed significant differences in the exercising group(p<.001). To summarize the results above, it is suggested that the 12-week boxing aerobics program can improve body composition, blood constituents, and the blood circulation, which may prevent or enhance relevant diseases such as cardiovascular disorders.