Recently, as concerns about environmental improvement have increased, various environmentally friendly transportation services have been developed and introduced. However, the effect on the introduction of such services has been not analyzed through a systematic methodology and process. Therefore, this research aims at suggesting a framework to analyze the effect of an environmentally friendly transportation service and investigating the validity of the framework. To the ends, a process to analyze the degree of improvement in transportation systems and environments, the linkage with existing policies, and profitability of the service is proposed. In addition, the concept and value of carsharing service, a representative environmentally friendly transportation service are explained and then the effects of the service are examined in terms of the aforementioned analytic areas, respectively. The results of this research can be utilized to provide the validity of a newly developed environmentally friendly transportation service and reflected to the policies of transportation and environment.