Abstract: Based on a highresolution and wellvalidated FVCOM model, a saltwater intrusion forecasting system in the Changjiang Estuary has been set up.A WRF model is also applied to predict the wind speed and direction in the Changjiang Estuary and its adjacent sea. The forecasting system can forecast threedimensional spatial distribution of salinity in the Changjiang Estuary at each moment during the following three days (72 hours).The forecasting system downloads the forcing data, runs the WRF and FVCOM model, visualizes prediction results and publishes the results. All the above operations are automatically processed by computer.The system was validated by hindcasting salinity of two stations, which are Baozhen and Chongxi at South Branch, during January 2011. The comparison of salinity between system hindcasted value and observation show the system is reliable. The system, with advantages of convenient operation and automatic procession, forecasts the saltwater intrusion in the Changjiang Estuary easily and timely.

Key words: Changjiang Estuary, saltwater intrusion, automatic forecast, FVCOM