In this thesis, it describes that spirit is the regenerative power in heritage design, and explained how it was inherited from past and still remain alive nowadays. A certain kind of method will be approached to help with the research on this topic. Since heritage design is the re-design based on the existing building, historical research places an important role during the architectural research. It shows the memory of the site. However, besides historical value and age value, other values such as use value, newness value and rarity value should also be considered in the value assessment, which makes decisions between demolishing, reserving or redesigning more convincing. Furthermore, the value assessment encourages architects reflect on history and find strategies for new design fit for the nowadays and look to the future. The value assessment can help find out the spirit of the heritage and the spirits of the can help to bring building into new life.