Electric power real-time balancing-dispatching & trading is the key to insure the secure and stable operation of power system， and is one of the important parts of competitive electricity market and an important content in the electric power grid dispatching decision-making. In this paper， the electric power real-time balancing-dispatching mechanism， the design and operation flow of real-time balancing market， the bidding of generators， the determination of the real-time dispatching schedule and its security correction mechanism， on-line correction mechanism of power system congestion， real-time balancing ancillary services， real-time balancing market price clearing and settlement mechanism are analyzed and studied. In order to avoid the market gamble behaviors， the coordinated relationship between the ahead time that the market members declare the bidding data in real-time balancing market and the real-time balancing market price clearing mechanism is discussed. Finally the structure and functions of electric power real-time balancing dispatching and automatic control system are presented.