The purpose of this study was to investigate the correlation between pulmonary function, quadriceps activity, depression and health-related quality of life in patients with chronic obstructive pulmonary disease. and 31 patients with chronic obstructive pulmonary disease who were diagnosed and treated at A hospital in Jeollanamdo were selected. There was a positive correlation between FEV1 and Rectus femoris(r=683, p<.05), Vastus medialis (r=0.653, p<.05) and Vastus lateralris(r=0.711, p<.01). but depression(r=-0.681, p<.05) and health related quality of life(r =-0.755, p<.01) showed a negative correlation. and FEV1/FVC and health related quality of life were negatively correlated(r=-0.623, p<.05). and Rectus femoris and depression(r=-0.618, p<.05) and health related quality of life (r=-0.683, p<.05) showed a negative correlation. and Health-related quality of life(r=-0.702, p<.01) also showed a negative correlation with Vastus lateralris and depression (r=-0.633, p <.05). Clinically, active intervention interventions are needed to increase pulmonary function, depression, and quality of life in relation to limb strength, especially fatigue of the knee ligament, while increasing activity.