Abstract: In order to meet the demands for informatization, network-based and standardization of crop pest data, and for the daily work of the technical staff of plant protection station, a WebGIS-based pest database and an automated warning system(WPDAWS) were built using the free open-source software including PHP, Apache, MapServer and MySQL. An open-style design mode was used in this system, which provided a powerful platform for different users to mange their data, such as the users from province, city or county plant protection station. The registered users have a permission to establish and manage a standardized pest database according to their own requirements, through the dynamic menu tree and data table design online system. The system can analyze and show the macro geographic scale pest data using the Web-GIS. The system can process the originally rough data of field investigation automatically and then make a short-term pest and diseases forecast. The mathematical statistical analysis module was integrated into this system which can help users to build a medium- and long-term forecasting model for the crop pest and disease. In addition, this system is easy to operate, so it has a strong and broad application. It is helpful to strengthen the information management of the crop pests through the network and to make macro decisions.