Researches on method for quantitative analysis applied with decision-making in consideration of variation in risk factors based on GIS(Geographic Information System) concluded as follows. Firstly, by way of decision-making in consideration of variation in risk factors, quantitative analysis performed for the existing route was applied to the new route, which would bring about reliable criteria in route planning and basic design stage. Secondly, horizontal and vertical alignment were easily available out of GIS for relatively speedy design and analysis with three dimensional alignment by decision-making in route planning. Thirdly, automation of route alignment is possible by utilizing quantitative evaluation system established in this research so that a risk analysis can be carried out in a relatively short time. Therefore it will eventually contribute to further development of road design technology.