Modal Shift from road to rail has been adapted in several countries as one of effective ways of reducing CO2 emissions caused by transport. Generally, effect analysis of CO2 reduction toward modal shift is calculated mainly from use stage and less consideration from other stages of life cycle, even though, in some case of modal shift needs that new line construction or new vehicle manufacturing. In this study, modal shift effect analysis is performed with considering construction, manufacturing vehicle and use stage. As a result we can get total CO2 reduction effect using life cycle thinking and check the necessity of including other life cycle stage not only considering use stage. In conclusion, there is no CO2 reduction effect if the reduction amount of CO2 in use stage is not bigger than allocated annual amount of CO2 in construction and manufacturing vehicle stage. According to this fact, analysing CO2 reduction effect of Modal Shift should be considered not only the use stage.