This study is to develop a specific fitness training program for national boxers and apply it for 14 weeks to find out the effect on specific physical fitness. The results obtained through this study are as follows. First, mixed power circuit training for national boxer was developed by consisting of flexibility training and power circuit training for the purpose of strengthening flexibility, muscle strength, power and cardiovascular endurance. Second, the results of applying mixed power circuit training during 14 weeks showed a significant improvement in the flexibility, the maximal strength of the upper body, the isokinetic knee strength, the power endurance of the lower body, and the AT (anaerobic threshold) level. In conclusion, mixed power circuit training considering the physical fitness and technical factors of boxers showed results in enhancing specific physical fitness. And it is expected to help provide basic data for establishing a systematic training system for national boxers.