This thesis investigates a factory's transformation from declined industrial area to the humanized public space. With the rapid development of China's economy, many old industrial areas in cities gradually fall into the plight of survival and development. In the early time, the renewal ignored the value of the old industrial areas. On the other hand, due to the original characteristics of industrial areas, they are facing challenges to be humanized public areas. This article starts with the background of current industrial areas renewal and points out the problems. In the next section, theoretical framework on the evaluation of old industrial areas, old industrial area preservation and humanized reconstruction are established to be the guide and principle of the case study. The successful case, Shanghai EXPO Urban Best Practices Area is chosen to find out how to seek for the balance between preservation and reconstruction into humanized public areas. Then the article establishes a relatively complete framework for planning and design, and demonstrates the framework through the design proposal of Shanghai Yangpu Auxiliary Equipment factory. This research serves as a practical model for preservation and reconstruction from old industrial area to the humanized public space. In addition, it also discussed and rethinks deeply over the problems of reusing old industrial areas.