The current conservation work of Nanjing, a famous historic and cultural city, is at a rather complicated state. On the one hand, the 30-year constant protection has made the conservation planning more and more perfect; on the other hand, the conservation work confronts with much pressure in reality such as urban modernization and old city renewal. Consequently, it is urgent that we step out of the current state which is dominated by specialized departments and experts, and convert from a merely technical level to a macroscopically social and economic level, and explore the conservation thought, strategy and approach of famous historic and cultural city from multi-dimensional perspectives under the background of new urbanization. Based on this view, the paper summarizes the development process of the establishment work of the previous three versions of conservation planning of the famous historic and cultural city Nanjing, and analyzes the realistic background of large-scale development and the old city renewal of Nanjing, and then discusses the problems in the conservation work and their causes. Moreover, some new planning suggestions are also put forward in the aspects of position and function of Nanjing as a famous historic and cultural city, pattern protection, evacuation policy and protection mechanism, from the perspective of cultural inherence under new urbanization.