This study aims to clarify the characteristics of Public Domain by analyzing the regeneration plans of the Industrial Heritage. The analysis of actual regeneration cases of industrial heritage revealed the following principles which took significant roles in constructing the public domain. Firstly, isolated and closed space in the industrial heritage is reconstructed as a multiple open space in order to organize the interrelationship between the urban space and architecture. And those multiple spaces are constructed as a sociopetal space by architectural settings. Secondly, industrial landscape and comtemporary architectural elements are combined to contrast old and new. Thirdly, industrial heritage is reconstructed as a organic space which has flexible attitude toward the social change and participation of civic groups. The results of the analysis shows that the regeneration of industrial heritage is building the foundation for reviving the city and healing its wound without sacrificing its historic place. Moreover, the regeneration of industrial heritage is an alternative plan to expand the public domain by creating the urban open space and the mechanism of sustainable spacial environment.