The objective of this study is intended to propose plans for reforming environmental impact assessment(EIA) systems by reviewing the current legal systems of EIA related laws and their implementation status in Korea, and by comparing the Korean situation to EIA systems in several foreign countries. This study tried to integrate all EIA related systems scattered over several laws into one comprehensive EIA law, and also to develop legal procedures necessary to accomplish the legislative purpose of the integrated EIA law. Therefore, I propose four reforms (1) All EIA systems should be integrated into one comprehensive EIA act. (2) Administrative plans and policies, though environmentally harmful, which are not currently subject to any prior consultation system, should be covered by the prior consultation system. (3) A screening or scoping should be adopted. (4) Widen civil participation should be encouraged and the administrative control enforcement and introduction of group litigation or citizen suits would be considered.