For patients suffering from spinal cord injuries, both of the possibility of having complications with the respiratory system and the related fatal rate are still high, while pneumonia is the most important cause of these fatalities. This research was carried out to find out what effects does a breathing exercise have on the respiratory functions and the improvement in the quality of life. The study was carried out for male patients suffering cervical spinal cord injuries for the purpose of inspiratory muscle strengthening. The objects of the study were 17 non-smoking-at-present male patients with C4 to C6 cervical spinal cord injuries. They had practiced inspiratory muscle strengthening training for three times a week for six weeks. The quality of life and the dyspnea (breathing difficulty) were self-measured before and after the training. As a result, the change in respiratory function was only significantly reduced (p<0.01) within the chronic group. In terms of the changes in the quality of life, the sub-acute group has only seen a significant improvement (p<0.05) for the VT(vitality), while the chronic group has seen significant improvements(p<0.05, p<0.01) in: GH(general health); BP(back pain); and VT(vitality). In this research, the inspiratory muscle strengthening has reduced the dyspnea (breathing difficulties) and improved the quality of life.