This was a pre and post test group clinical trials held in pulmonology outpatient clinic in Dr. Moewardi general hospital Surakarta from January to February 2018 using purposive sampling. The COPD group C and D patients were cathegorized as intervention group which received allopurinol 300 mg/day for 4 weeks and control group which did not receive allopurinol. Glutathione sulfhydryl serum level, %VEP1, 6MWT, and CAT score were measured at baseline and after 4 weeks in both groups.Results: A total of 37 stable COPD group C and D patients were included in this study. The intervention group showed decreased of GSH level (52.58 ± 38.39) µg/ml and CAT score (10.37 ± 4.46) which were statistically significant compared to control group (p<0 p=0.94). p=0.005) p=0.109) p=0.057.  >Conclusion: Allopurinol decreased GSH serum level, didn’t influence %VEP1, increased 6MWT, and decreased CAT score of stable COPD group C and D patients.Keywords: COPD,  allopurinol, GSH, %VEP1, 6MWT, CAT