In recent years, architecture culture study is a popular direction in traditional vernacular dwelling research of China. Architectural culture, as the metaphysical part of a building, not only influences the formation of the building in design period, but also dominates the usepattern of the building after construction. However most of studies started with material form of dwelling from architectonic prospective ignored that architecture is a phenomenon of culture. The study of vernacular dwelling from cultural and other related academic fields is very necessary. Bei-nong is a transportation space in traditional vernacular dwelling of Jiangnan area in China. This paper tried to use the methods of urban history research to investigate this space. First of all, the particular time and region of bei-nong appearance has been observed and defined from historical and cultural background. Then, appearance reasons have been analyzed based on the social context and mainstream philosophy during the scope of time and region. In the end, the physical and social functions and the architecture construction of bei-nong have been summarized and ratiocinated from the former conclusions according to inductive reasoning theory. A real and comprehensive bei-nong is showed in the result of research, not only the physical form and history of architecture but also a history story about that place and time.