Since Taejongdae Resort Park’s designation as the first tourist area in 1969, a total of 230 domestic tourist areas have been designated, constructed, and operated thus far. Forty-seven years after the first tourist area designation, 38.8% of domestic tourist areas are now in a stage of stagnation/decline. As these declining domestic tourist areas only play their role as normal tourist areas during peak season, this study examined the causes of decline in tourist areas in general and of each tourist area in particular, so that the analysis could be used as basic data for the regeneration/revitalization of tourist areas. In order to understand the causes of decline, an index of cause of decline in tourist areas was drawn up. Data were collected based on this index, with tourist areas in the stagnation/decline stage as the target, which was drawn from previous research. Based on the results, factor analysis was conducted on both decline cause and discriminant analysis to understand the causes of decline in each tourist area. The results demonstrate that the diverse uses for tourists, sustainability, and preservation of tourism resources have a huge influence as internal factors, while the external capital investment and competitiveness of tourism resources have a huge influence as external factors. As this study only analyzed the quantitative index in accordance with physical characteristics, it is necessary to conduct additional research based on qualitative indices. In this case, this study could be used as basic data. This study is expected to be applied as basic research to seek solutions for each cause of stagnation/ decline in tourist areas, and also to establish measures to regenerate/revitalize those areas.