利用地理資訊系統(Geographic Information System, Gis)疊圖分析選址方式比傳統方法更爲有效，然而要如何釐清GIS選址模式中立地條件(Location)複雜之權重與如何建置GIS自動化選址模式，確實是値得探討的問題。本文以台北市百貨公司爲例，考量利用GIS自動化選址時立地條件中之各項因子，並建置台北市百貨公司GIS自動化選址模式，以瞭解被分析利用GIS選擇出之台北市百貨公司新址之空間分布。本研究GIS選址模式之立地條件，綜合零售理論中Reilly的零售吸引力模式、Converse的引力平衡觀點、Huff's的機率法則與Carey's模式作爲立地條件各因子之量化原則，並評估選出人口(Population)、易達計(Accessibility)、吸引力(Attraction)、發展潛力(Developing Potential)與競爭力(Competition)五項因子，並依各因子之細項分別建置GIS選址模紐，用以評析百貨公司商圈與台北市百貨公司設店新址之空間分布。經利用GIS選址模式進行台北市商圈分析興百貨公司自動化選址操作，獲得之台北市商圈與百貨公司設店空間分布結果與台北市實際設店地點大致相符，證實利用GIS模組化疊圖分析選址方式，確實比傳統方法更爲有效。

Using Geographic Information System (GIS) coup overlap operations to carry out Site Selection is more efficient than traditional methods. How to determine the complicated weight of Location factors in GIS site selection model and how to establish a GIS automatic site selection model are both important issues to discuss. In this article, using new department store site selection in Taipei city as an example, we decided weights of Location factors for establishing the GIS site selection model in order to analyze spatial distribution of selected new department store locations in Taipei city. In this study the Location factors and the rule of quantifying data in the GIS site selection model are based on retail theory of Reilly's Principle of Retail Gravitation, Converse's Breaking-point concept, Huff's law and Carey's model. The essential Location factors we chose for the GIS site selection model are Population, Accessibility Attraction, Developing Potential, and Competition. By choosing and transforming the quantifiable data which corresponds to the Location of the site selection, we established GIS site selection sub-models for each Location factor. After GIS overlap operation, it can he seen that the selected department store sites of the resulting map mare or less correspond to reality in Taipei. There are benefits in improving the efficiency of showing spatial distribution for the selected locations. The study also shows that using GIS operation is appropriate for site selection, and can achieve better results.