The main purpose of the study is to empirically investigate the factors affecting the decline of industrial parks developed by Local Government. For this purpose a new index, so called MDI(Multiple Decline Index), is constructed in order to measure the decline of the industrial parks. A multiple regression analysis is attempted, based on the index, to derive the factors influencing on the decline of industrial parks. The major findings can be summarized as follows. First, it turns out that the decline of an industrial park has been influenced by the internal conditions of the industrial park itself as well as the external circumstances of the surrounding city. Second, the total area of industrial park was identified as the only variable which is statistically significant among various variables representing the internal conditions of the industrial park itself. Third, three variables related to the external circumstances of the surrounding city turn out to be statistically significant such as a number of manufacturing company, new dwelling ratio, dilapidated dwelling ratio. These findings strongly suggest that the regeneration policy toward the declined industrial park should consider changing conditions not only of industrial park but also of the surrounding city.