This study addresses the topic of suitability analysis for helping with land use planning, which is one of important decision-making in urban planning, utilizing geographic information system. Covering the Kumi City before integrating with neighbor county, the site suitabilities for land uses, which are categorized into residential, commercial, industrial and green, were analyzed using the overlay method based upon the database constructed for this study. In the process, assessment criteria which include environmental factors and relative weights were determined and also the land use/cover map and NDVI map which were generated through satellite image processing were included in the database. The suitability maps by four function spaces were derived according to the grade and compared with the present land use state and the land use concept map of urban master plan. For more accurate analysis, practical developing plan, land price data, soil data should be included. Also if the demand estimation data by each land use had been added, the reliability of location allocation could have been raised.