Increasing water productivity with improving and enhancing agriculture practices becoming biggest target of worldwide country especially in developing country i.e. Egypt .Simulation models, such as the DSSAT (Decision Support System for Agrotechnology Transfer) Crop System Models are often used to characterize, develop and assess field crop production practices. In this study, one of the DSSAT Cropping System Model; CERES-Maize was employed to characterize maize (Zea mays) yield, water use  and nitrogen uptake  at  Sids,  Beni Swief Governorate  condition in Middle Egypt ( Lat. 29º 04' N, Long. 31º 06' E and 30.40 m above the mean sea level). A field experiment was conducted including three water regimes  (irrigating at 100%, 85% and 70% of reference evapotranspiration (ETo) and three nitrogen levels (216, 288 and 360 kg N/ha).After success model calibration with data collected from two distinct growing seasons (summer 2013-2014 ) ,the  model was used to predict the grain yield, ET crop and N uptake. Then, validation was done and, results showed high correlation between simulated versus observed data with values of correlation coefficient (R²) ranged between 0.92 and 0.99. Running simulation showed that increasing soil water content increased simulated grain yield and ET crop while N uptake was not effected by increasing soil water. Yield was positively affected by increased N-level and maximum simulated values were obtained at 336 kg N/ha but the ET crop increase was limited due to increase N levels. These outcomes indicate that such model can be used to improve our understanding of the effects of irrigation and N fertilizer management practices on maize yield especially  if the long-term irrigation and fertilizer management practices strategy have been adopted under study region conditions.