Abstract: The main characteristics of urban geologic map and its compilation principle and methods are discussed in following: (1)The significance of compiling urban geologic map is to meet the needs of urban construction and development, to make the geologic work better serve the overall plan and government decision making, and to provide basic data for practical engineering design and construction, and then to provide a scientific basis for rational development and use of urban land resource and conservation of urban geologic environment. (2)Urban geologic maps represents a series of maps, aiming at professional geologic planning, meeting, engineering geologic demand, and used for overall benefit evaluation. They are systematic maps with diverse functions that meet the demands of geologists , urban planners and designers as well as government policymakers, respectively. (3)Principles for compiling urban geologic map are:① objectivity; ② evaluation character ;③ Prediction character and ④ practicality. Objectivity, evaluation, and calculation are the precondition and basis, and practicality is the objective. Urban geologic map should be accurate, distinct, and readable. Its compilation must accord with the demands of city planning and government decision for geological technology. (4)Urban geological map includes three grades of maps with different functions, such as basic geologic map, and maps for analysis and evaluation and benefit decision evaluation. The compilation method and representation pattern must reflect the unification of grade contents nature use of maps, and the unification of technology, management, and policy decision.