Abstract: More and more metro railway construction in China adopt fully automatic operation (FAO) system. In this paper, the application necessity and definition of the operation scenario for FAO system are discussed. It is proposed that the definition of FAO system operation scenario should ensure the integrity, take into account of the operation safety and consider the essential requirements, such as the function requirements, safety requirements and performance requirements. Finally, the design and application of new operation scenarios in Taiyuan rail transit Line 2 project are introduced.