The Central City Work Conference puts forward that we should retain the unique "gene" such as geographical environment, cultural features and architecture style of a city. In the era of fierce city competition, a city having competitive advantage must be a city holding its own unique "gene", the traditional characteristics and the differences from other cities. In order to retain the unique “gene” of a city, archives should play a more important role and have a new mission. Archives are the recorded matter of urban landscape gene, the heritage matter of urban culture gene and should be the symbols of urban spirit gene. We should retain the unique “gene” through the record and inheritance function of archives and the new mission of archives in urban construction and development so as to highlight a city's personality and charm.