The operation and function of the improved meso-scale n umerical foreca sting operational system of the Shenyang Regional Meteorological Center are desc ribed. The system is put into operation in 1997. At first, the system provided o nly precipitation forecasts, and recently it is able to provide such operational products as precipitation forecast, tropic cyclone route forecast, meteorologic al condition forecast of air pollution, service guides of precipitation enhancem ent and basic meteorological element forecast needed by the operational urban en viro nmental meteorological prediction. The system runs twice every day automatically . The products directly enter the graph system of MICAPS, Vis5d and Grads to dis play charts and directly enter meso-scale numerical forecasting web pages of th e Shenyang Regional Meteorological Center Local Area Network. The forecasting prod ucts have become necessary reference data for forecasters. According to the asse ssment made by the Shenyang Central Observatory, its forecasting accuracy exceed ed the Japanese East Asia Model in the flood season of 2002.