Environmental Impact Assessment (EIA) in Korea has worked toward environmental conservation and decision making since the Environmental Impact Statement of 1981. In order to implement the EIA process effectively, we have developed a system for and various methods of EIA. Among these methods, the Environmental Information System, which was introduced recently in Korea, can be used to integrate geographic and attribute data effectively. This study includes methods by which we may use the Environmental Information System. First of all, it explains building EIA factors on the natural environment, the living environment, and the socio-economic environment defined by Environmental Impact Statement regulations in Korea. This study also presents some applications of the assessment methods concerning suitability analysis of landfill sites. Finally, it shows the effectiveness of the Environmental Information System in odor impact assessment. Based on these analysis, the study makes some conclusions for the applications of the Environmental Information System.