The legitimacy crisis of public administration has a long history. From a historical perspective, an analysis of five Western pathways in the discipline of public administration shows that the roots of this crisis lie in the lack of a public nature. From a theoretical perspective, the “publicness” of public administration should be defined along the dimensions of public administration powers, actors, targets, methods and values. In terms of practice, the uniqueness of China’s public power framework, the influence of traditional political culture on the public nature of Chinese public administration and the provisions governing this public nature at different stages of China’s development constitute the unique public nature of the construction of Chinese public administration. The discipline construction of Chinese public administration should be rebuilt so that its public nature forms the basis of its legitimacy, in accord with historical logic, theoretical logic and practical logic. We should construct a publicness discourse system of Chinese public administration that adheres to the value guidance of publicness and should frame research topics on the basis of publicness. This will ultimately form a research paradigm for the public nature of public administration.