Saturated storage and excess infiltration of two water resources model was modified for each characteristic and mechanism of saturated storage and excess infiltration model and Tank model, based on the introduction to two models. The model could reflect dynamic change of surface runoff, interflow and groundwater runoff. And it can be applied in flood forecasting, river simulating, and water exploitation. The modified model was applied for the Luanchuan Station in the Yihe River Basin. Three optimization algorithms (Genetic, Rosenbrock and Simplex) for hydrological model calibration were used for calibrating the model parameters. The modified model was compared with the original model. The results show that the modified model has a better goodness-of-fit than the original model, and the model could reflect the process of different runoff composition