Abstract: In this paper,the SMAR (Soil Moisture Accounting and Routing) Model is briefly reviewed with a special addressed on it srevision-the distributed and flexible time-intervals model which were made during this study course.The auto-optimisation technique of the model parameters,the flow routing method and the real-time updating theory which were employed in the developed system are discussed.The features,menu system,and basic requirements of the developed system are briefly introduced.As one case study,the application results of the system in the Three-Gorges catchment on the Yangtze River are presented and discussed.