According to the following two sets of Chinese specifications: Technical Specification for Developing Integrated Supervision and Control Systems in Smart Substations and Function Specification for Integrated Supervision and Control Systems in Smart Substations， the necessity and importance of developing the integrated supervision and control system are presented. The scope， structure and function architecture of the system are described. Key devices used in the system are treated. The network structure of the system and detailed project configuration scheme are discussed， which is helpful to deeply understanding the above two sets of specifications and promoting the development of the system.