This study was intended to standardize the Korean version of dysfunctional attitude scale. Participants were normal adults 3,708 and depressed patients 142 selected from 12 administrative districts(Do). Internal consistency was calculated and construct, concurrent and discrimination validation were performed. And ROC analysis was used to testify diagnostic efficiency for depressed patient. K-DAS was reliable (Cronbach α=.86) and consisted of 3 factors. Correlation Korea Depression Scale and K-DAS was .46. Maximum diagnostic efficiency was 61.1% in cutoff score 162. Factor 1 'performance evaluation and perfection' among 3 factors had the highest diagnostic efficiency. These results suggest K-DAS be reliable and valid tool in diagnosis and treatment outcome evaluation. Finally, the limitation of this investigation and future research tasks was discussed.