Yukihiro TANIMURA Structures Technology Division Recent Research and Development in Structural Technology Recent research and development into railway structures at the Railway Technical Research Institute has focused on maintenance of existing structures, seismic retrofitting, development of construction technologies considering performance and economic efficiency and environmental countermeasures for comfort improvement, etc. This review firstly describes technologies for monitoring and diagnosis of existing structures. Secondly, it describes technologies to improve the performance of existing structures and stations, such as noise reduction, spatial expansion and creating more pleasant and user-friendly stations. Finally, it describes technologies for seismic countermeasures, including earth structures with high resistance to tsunamis and improvement of seismic performance of existing structures.