Railway Intelligent Transportation System (RITS) has been initially proposed in this chapter. Being a railway transportation system of this era, its basic purpose lies in strengthening safety of transportation, raising transportation efficiency and improving service quality. Compared with Intelligent Transportation System, RITS has the same research purpose, emphasis and similar advanced technology has been adopted. The substantive characteristics of RITS is a complex, distributed and open system, belonging to the category of Open Complex Giant System (OCGS), the meta-synthesis method being qualitative and quantitative is integrated for the research of OCGS. Finally, the development of RITS in China and the current research in Japan, USA, and Europe etc. are introduced in this chapter.