Purpose: This study aimed to define the relationship among self-care, symptom experiences, and health-related quality of life(HRQoL) according to the severity of disease in chronic obstructive pulmonary disease(COPD) patients. Methods: The participants, 195 COPD patients, were recruited at a pulmonology clinic of a universityaffiliated medical center in B metropolitan city. Inclusion criteria were patients who were diagnosed as COPD and had less than 0.7 of $FEV_1$/FVC(Forced Expiratory Volume for 1 second/Forced Vital Capacity) ratio. The severity was classified with GOLD(Global initiative for Obstructive Lung Disease) stages, $FEV_1%$ predicted value from mild to very severe. The data were gathered by the medical records and self-reported questionnaires. Results: The self-care, symptom experience, and HRQoL were all significantly different by COPD severity based on pulmonary function(p<.05). There were significant moderate negative relationships between symptom experiences and self-care(r=-.54, p<.001) and between symptom experiences and HRQoL(r=-.64, p<.001). There was a moderate positive correlation between self-care and HRQoL(r=.63, p<.001). Conclusion: It suggests that the assessment of disease severity based on pulmonary function and subjective symptom experience in patients with COPD may be a key component to develop a tailored self-management program and to improve their quality of life.