The infrastructure， functions and operation flow of power provider oriented electricity market management system are introduced， by which the collaboration is supported between power groups and their power plants for assisting bidding decision-making in electricity market. The system consists of two subsystems. One is deployed at power provider group company， and its main functions include collection， process and analysis of information from transaction management， power plant operation and inner production and management system， market parameter forecasting， bidding decision-making， risk evaluation and services providing for authorized users in power provider groups and their power plants. The other is deployed at power plants， and its main functions include information collection of electricity market and power plant operation， cost analysis， bidding decision-making and settlement management. The presented power provider group oriented electricity market management system is implemented based on J2EE software architecture， and has been put into use in East China regional electricity market.