Abstract: MESIS (MEteorological Service Information System) is a new generation system with GIS, database, visualization, multimedia and Web technology integrated to produce and share comprehensive weather service products in National Meteorological Center and provincial meteorological departments.The purpose of the system is to further improving the means and the quality of meteorological services, to establish a meteorological service platform providing rolling, continuous and customized products that can satisfy the needs of government decision making and social developing. The completion of this system will accelerate meteorological service of China to catch up with the international level.The MESIS has four main advantages: The rich geographical information, high quality graphics and outputs, powerful meteorological information statistics and analysis ability, and the open system architecture. It includes four kernel modules, the meteorological information management module, the data processing module, data statistic and analyzing module, and the service products producing module. So far, the MESIS has been widely applied in national and provincial meteorological departments, achieving satisfying results.The platform architecture, design of functions, and key technique, e.g., the GIS application are introduced. The implementation of meteorological information retrieving and visualized product producing are figured out. The problems during the construction of this system are also discussed in details, and the proper solutions are also given in the consideration of various factors. The key technique of this system has also been described in depth.