Reclamation project is very efficient development plan which saves the sea to create new land in case of Republic of Korea where the population density is high and urbanization is still in progress. However, reclamation project is necessary to be managed consistently because to install the artificial structures in natural terrain may cause the environmental change. Thus, in this study, we suggested the remote sensing method as the efficient management plan about large-scale reclamation project and derived quantitative environmental change based on this method.