Abstract: At present, cyberspace mapping technology is one of research hotspots in the field of network security and a development trend in the future. A brief introduction is made to knowledge graph and cyberspace mapping and key technologies for mapping knowledge graph of information assets are also discussed. To meet the development need of railway network security, the intention of mapping knowledge graph of railway information assets is addressed and a categorical plan of railway information assets is given. Meanwhile, phase division of mapping knowledge graph of railway information assets and the objectives of each phase as well as main tasks of mapping knowledge graph of railway information assets are proposed, indicating the directions of related researches in the future in this respect.