Recently, localized rainfalls and torrential typhoons due to the abnormal climate have increased in Korea and the damage situation caused by debris flow at Umyeon Mountain has especially take place a big social issue. However, the standardized damage investigation does not yet exist and the systematic analysis of the data has not also been carried out. In this regard, this study developed assessment factors to conduct standardized damage investigation for debris flow. To achieve this, preliminary assessment factors were derived from analysis of literature review and the Delphi method through 12 experts who work at fields of facility, academia and industry. As a result, 29 rational check lists of 6 groups were determined.