Abstract: Shanghai meteorology bureau has built its seamless grid forecast products with different forecast elements and resolution for term rang from 0 to 45 days. In this article, the objective forecast technologies and operation systems used to form the grid forecast were briefly introduced. A background grid-forecast was made without manual intervention for the requirements on (1) 0-6 h blended quantitative precipitation forecast consisted with current observation; (2) 24-240 h consensus forecast of calibrated operation NWPs; (3) 11-45 d extended-range forecast. Finally, forecasters would give edit and publication on to the grid forecast with the help of our integrated forecast system and forecast evaluation system. By means of these objective tools, the grid forecast was able to get demanded precision without adding more burdens to forecasters.