Transportation is not only instrumental methods of moving, but also constitutive mobile technology, which in?uences the lifestyles, modes of interaction and everyday sense of people. In this article, we try to understand the constitutive role the urban rail transit has played in Shanghai through the analysis of the vicissitudes of Shanghai rail transit from 1980 to 2010.It is found that from metro, elevated railroad to maglev, the vicissitudes of Shanghai rail transit in the city's second globalization period can be taken as kind of “communication”. Shanghai mass rail transit has undergone a transformation from a symbol of reconstructing modern Shanghai, technological splendor and city card beyond natural restriction, urban construction that arouses awareness of rights protection and new social movement, urban public facilities pending improvement, to public stage demonstrating civilized etiquette. Shanghai mass rail transit not only has always something to do with different urban meanings, but also initiates complex cultural politics between the global and the local, and profoundly in?uences how the city is experienced and imagined. As a point where powers of different scales from the global to the local meets, con?icts and divergences, Shanghai rail transit system functions as an in?uential infrastructural medium. It changes the meanings of both the city and itself and facilitates the reconstruction of the global-local relations.