Due to high-cost effectiveness by low construction cost and high performance in long-term maintenance and against heavy rains, floods and severe earthquakes, various type Geosynthetic-Reinforced Soil (GRS) structures have been constructed for high-speed railways (HSRs), as well as ordi-nary railways, in place of conventional type ones. An about 66 km-long new HSR line (i.e., Kyushu ShinKanSen Nishi-Kyushu Route) is now under construction to be completed in 2022. To protect the aquatic environment in the adjacent mountain areas, the tunnel level was raised higher, which increased the number of relatively short tunnels, therefore increased the number of elevated structures to be con-structed in valleys between tunnels. To meet this and other design conditions, GRS RWs with a total length of 5 km, 80 GRS bridge abutments, 55 GRS tunnel entrance protections and 7 GRS integral bridg-es, which is densest ever for railways, were adopted. This paper outlines this project.