In this study, 2-dimensional inundation analysis of flow aspect, inundation area, averaged inundation depth, maximum inundation depth was implemented according to application of topographical data in urban area where the population and buildings are concentrated. In terms of building topographical data, there are several methods: DSM(Digital Surface Method) constructed around big city using LiDAR survey, digital map drawn on a scale of 1 to 1,000 and combination of DEM(Digital Elevation Method) removed building, plants and trees and digital map. Also, the topographical data generated on the basis of above-mentioned methods were converted other topographical data at resolution of 4m, 8m and 16m. The inundation caused by the localized heavy rain event on Sep. 21th, 2010 was analyzed in and around samsung drainage flooded at that time by each resolution. The results of inundation analysis was expected to suggest optimal method for building topographical data and resolution in order to exactly and effectively analyze inundation. Consequentially, in case of applying for generated topographical data by combining DEM and digital map data and higher than 4m resolution, the superior result was shown.