Excessive nitrogen (N) and water use in North China Plain (NCP) are threatening the sustainability of crop production and quality of groundwater. To quantify the sustainability of different management practices, field research under a variety of irrigation and N management has been conducted in many locations within the NCP. In this study, the Root Zone Water Quality Model (RZWQM2) and DSSAT4.0 were evaluated with data from four N treatments (0, 100, 200, and 300 kg N/ha) in an auto-irrigated wheat-corn double cropping system from 2000 to 2002. In general the models responded well to different N nitrogen managements. Simulations of soil water, N uptake, and crop biomass and grain yield better than soil nitrate-N. The model was further applied to evaluate the effects of current and alternative water and N management practices on crop yield, nitrate-N leaching, and water and N fertilizer use efficiency in the NCP. Simulations showed potential saving of about 60% of the current N application levels in the area that can reduce about 90% of the nitrate-N leaching to ground water under current management practices maintaining the current grain yield level.