疊圖分析為資源與土地使用規劃的一種分析技術，主要乃綜合多項環境因素以分析空間向度之資源分佈特性，並作為將資源有效且合理地分配與規劃之依撮:而地理資訊系統所提供之疊圖分析功能，可透過快速的電腦處理能力與多樣的分析功能，任何規劃作業都可迅速且精確地完成。本文主要目的即從疊圖分析之角度去瞭解其理念基礎與結構，並探討地理資訊系統應用於疊圖分析之功能及應用範疇。本文首先探討疊圖分析所應用之地圖代數架構與觀念，進而分析引進地理資訊系統技術後疊圖分析之程序架構:其次，從資料分類、疊合分析、連結與量測分析、及數值地形分析等四類功能，說明疊圖分析應用地理資訊系統之功能與技術。本文並以環境敏感地區劃設、土地使用適宜性分析與路廊選線為例，說明疊圖分析如何藉助地理資訊系統應用於相關規劃作業上。最後，本文由規劃應用之觀點，研提數項未來地理資訊系統在疊圖分析之發展建議。

Overlay mapping is an analytic tool for resource and land use planning， which can combine various environmental factors to analyze the spatial characteristics of resources for allocating and planning resources rationally. Throughrapid data processing capability and various analytic functions， GIS can provide useful operation tool for overlay mapping. The major purpose of this paper is to describe the fundamental concept and structure of overlay mapping process， and to provide further insight of the function and application of GIS. First， this paper addresses the structure of map algebra for overlay mapping， and the analytic framework of computer-assisted map analysis. Secondly， this paper discusses the functions and techniques of GIS's application for overlay mapping， which include reclassification， overlaying， connectivity and measurment， and digital terrain analysis. Finally， this paper further explains the application of GIS's overlay mapping capability for urban and regional planning by demonstrating the examples of the delineation of environmentally sensitive area， land use suitability analysis， and optimum siting of transportation corridor. Several suggestions regarding further improvement of GIS's overlay capability for planning implication are made to conclude the paper.