The main objective of this study is to examine the effect of Qi-training on the immune system, especially neutrophil bactericidal function. Nine healthy male subjects were studied for the effects of one bout of ChunDoSunBup (CDSB) Qi-training on superoxide (O2- production and adhesion capacity of neutrophils at times immediately after (Post I) and 2 hours after the Qi-training (Post II). The Qi-training enhanced O2- production, reaction velocity and neutrophil adhesion capacity and there were significant differences at Post I compared to before Qi-training (Pre). In addition, the number of white blood cells (WBC), monocytes and lymphocytes were changed significantly through Qi-training.Therefore, it seems that CDSB Qi-training may increase the resistance of trained individuals against common infection and inflammation.