Subway Line 9 was a project that revolutionized subway design in a completely different way from the planning and design process. From the beginning, designers and architects set a common goal, shared concepts, and started. This is a monumental project that first established and implemented all the elements of subway design that can be seen anywhere, by melting the design philosophy of users and spaces in all the existing ways that focused on efficiency and economy. Line 9 is a 25 stop along the south side of the Han River that divides the east and west of Seoul, and was carried out under the concept of <The Future Wave>. The concept of a more convenient human-centered space and an efficient space for maintenance is consistently applied to all history to unify the materials, colors, and standards of the finishing materials, and built-in signs, advertisements, and various facilities on the wall to make it comfortable and clean. Completed the interior space