Cultural sites，as the common civilization birthplace of human being，which connects the history with the modern，which is often the “soul” of the “city”，and which is an important symbol to build up the city culture image. In the digital age，cultural sites needs the contemporary “transformation” including the common care，the consensus，the symbiosis，the conspiracy and the jointly expectation. The history of Cultural sites belongs to “the first space”，and the present of the cultural sites belongs to “the second space”，meanwhile，the digital transmission of cultural sites has expanded the original space of city and is building “the third space”. In digital era，The protection and inheritance of traditional cultural heritage have been integrated with technology innovation，involving the inheritance of excellent traditional culture，the creation of contemporary culture，and the global strategy of national culture. The expansion of “the third space” causes specific effect on the establishment of city image and the development of city’s brand. As the first batch of national archaeological park，such as the old summer palace and Daming Palace，has strong representative in the digital communication of great ruins and the expansion of urban culture space.