With the application of system dynamics, a dynamic, nonlinear model (SDMUWEIC) was developed in this paper in order to reflect the relationships of population, economic, resources and environment. Through a systematic procedure of model validation and uncertainty analysis, the model was applied for predicting and analyzing the future market capacity and constituents of urban water infrastructure. It illustrated the volumes and trends of potential capital market in construction, general mechanical equipments and water treatment instruments as well as their relevant influencing factors including water pricing and urbanization rate. Several different scenarios were further under test to reveal the sensitivity of different uncertain components.