Abstract: Most of the existing Life Cycle Assessment (LCA) research in the field of transport is ex-post evaluation. This paper proposes an LCA method in the planning phase for evaluating life cycle carbon dioxide (LC-CO 2 ) emission from the provision of modal railway systems. As a case study, the Superconducting MAGnetically LEVitated (MAGLEV) transport system is examined. The LC-CO 2 emission factors with standard infrastructure are introduced in the inventory analysis for the LC-CO 2 emission. The change in LC-CO 2 emission by shifting from the existing inter-regional transport mode (ordinary railways, airplanes and motor vehicles) to the MAGLEV are analyzed by the Extended Life Cycle Environmental Load (ELCEL) concept. An environmental efficiency index considering speed and capacity is also defined and the alternative transport system evaluations are conducted. Key Words : Life cycle assessment (LCA), Environmental load, Transport infrastructure provision 1. INTRODUCTION Due to increasing concerns about global and local environmental problems, improvement of railway systems is preferred for their lower environmental load in operational conditions. However, there are few examples in which their effects were quantitatively inspected. Even though such effects were proven, the basis and method of estimation were rarely clarified. This study aims at developing a method which quantitatively evaluates carbon dioxide (CO