Abstract: In the contemporary context, along with the decline of public space due to the boom of virtual space and the globalization of capital, physical space is no longer the only source of media for establishing public attributes. In order to interpret the irreplaceability of physical space, this research identifies three layers of meaning regarding public space, and by tracing the physical space prototype of public space in the sense of origin (theatre), and the behavior model prototype of public space (ritual), explores the action mechanism of public space in constructing publicness, and proposes the triadic relationship of “space”, “behavior” and “emotion”. On this basis, the research further proposes that as a physical carrier of the aforesaid relationship chain, public space derived from theatre can act as a medium to bridge the material world and the spiritual world.