Background: The 2011 GOLD consensus uses symptoms to categorise patients according to disease severity and guide treatment. COPD Assessment Test (CAT) and modified Medical Research Council (mMRC) are both used to evaluate the symptoms. Purpose: To examine the discripancy between CAT and mMRC in patients with COPD. Methods: Patients were recruited from 49 centres in Korea, as part of the COPD cohort (KOCOSS) study. Results: Total 223 patients with COPD were eligible for analysis. Age was 68.0±7.6 (Mean±SD) and 88.3% were male. FVC, FEV1, and FEV1/FVC were 3.08±0.84 L (83.24±19.00%), 1.42±0.56 L (51.98±17.12%), and 45.88±11.52%. Mean CAT score was 16.27±8.36. There was sigificant correlation between CAT and mMRC (R=0.516, P＜0.001). However, mMRC was less than 2 in 60.0% of patients while CAT was less than 10 in only 21.2% of patients. Discripancy between mMRC and CAT were observed in 45.9% of patients. Conclusion: Although there was correlation between CAT and mMRC, discripancy between two scores was noted. Further study regarding CAT and mMRC in patients with COPD is needed.