By means of Tianjin, Tianjin Planning Bureau commissioned the Institute for Cultural Center of the city's comprehensive design work, we have a bold attempt to establish UIM in the project work ethic, that construct "Urban Information Model" digital city. The design and application of BIM from single building, community outreach to expand to the regional architecture, urban planning, the city's comprehensive design work truly BIM application stage expanded to UIM fields. We propose UIM-platform database meaning construction principles, UIM information model and task books and other digital city, digital city paper aims to propose the framework of the overall vision and research ideas, specific design and research is being phased, task, we deeply feel UIM platform to build the significance and hope that through practice, and finally to the advantage of BIM applied to urban design and preliminary work for the construction of digital cities to contribute.