In the planning and operation of power grid, various types of data such as generation planning, load forecast, network topology, electrical parameters, etc. are needed. At present, the statistics of these data are from different sources. Incomplete information is also existed. Therefore, this paper puts forward a design scheme of an integrated database management platform for power grid planning and operation to solve this problem. The integrated database management platform is based on a distributed software architecture and Oracle database for data storage, which covers all the data requirements for power system planning and operation and provides user defined component models. The scheme has been implemented in China Southern Power Grid. The platform provides data interface for all kinds of advanced applications.