Abstract: On the premise of unattended substations, the basic concept and functional orientation of the smart remote terminal unit（ RTU） and supervision and control terminal are proposed. The feasibility of the implementation of substation monitoring and control functions is discussed by using the smart RTU based supervision and control terminal. Some key technologies used in the implementation of substation monitoring and control functions through the smart RTU based supervision and control terminal are discussed, such as architecture, dual redundancy, supervision and alarm, five-prevention interlock, voltage and reactive power control, programmed operation, remote browsing. The limitation in supervision and control terminal is also discussed. The related technologies are finally verified by a testing system and actual projects.