Research conclusions：In this paper, the discussion is made on the resource sharing in the fields of vehicles, vehicle depots and the National Railway’s participation of urban rail transit, and resource sharing method is proposed in terms of constructing station and depot together, sharing forms of vehicles and their maintenance. Through adoption of same sytle vehicle, accessories, interfaces and technology for obtaining the consistency or compatibility, the max resource sharing can be achieved. In addition, taking Chongqing as an example, it proposes to use some parts of the national railway as some parts of urban mass transit in order to achieve the resource sharing and save construction cost.