The daily weather series simulated with observed weather data and weather data generated with conventional WGEN model taking dry and wet day as stochastic parameter and DWS model were statistically compared and analyzed. These three weather data were respectively used to drive maize growth simulation model. The corresponding yield results were compared. The results showed there was no significant difference between observed weather data and weather data generated with DWS model. The difference between yield simulated with DWS model and yield simulated with WGEN model was not significant.