Purpose: This study was conducted to examine the effects of walking exercise training on body composition and physical fitness in middle aged women. Method: The subjects were randomly assigned into an obese walking exercise training group (n=21), a non-obese walking exercise training group (n=9), or a control group (n=10). The women in the treatment groups were then subjected to brisk walking at 50~70% of maximum heart rate twice a week for 12 weeks. The results were then analyzed by repeated measures ANOVA using SPSS 12.0 for windows. Results: Body weight, BMI, % body fat, and WC were not significantly improved in the obese walking exercise training group and the non-obese walking exercise training group. However, muscular flexibility and muscular endurance were significantly improved in each of these groups (p<.05). Conclusion: These results indicate that 12 weeks of walking exercise training enhanced physical fitness. However, the treatment in this study did not improve the body composition of middle aged women.