由於可攜式行動裝置近年來快速成長，隨著行動裝置與地理資訊的結合發展出的適地性服務 (Location-Based Service, LBS)，也呈現越來越多的應用方式。LBS最基本的功能為定位，定位精度好壞也影響著LBS的應用面，越高的定位精度應用面越廣。常見的定位方式便是用GPS導航定位，但是在都會地區越是繁榮的地方往往過多的建物使衛星訊號被阻擋，導致GPS的定位會受到影響，造成平面誤差量會在15公尺以上，或是無法定位。利用都市區域有Wi-Fi訊號分布的特性，藉由區分不同的Wi-Fi訊號來源與接收強度，做出定位判斷，可以使原本GPS無法定位的區域，也可以利用Wi-Fi訊號來做定位。本研究嘗試使用高感度GPS接收器，在建物周邊定位，及在GPS無法運作時使用Wi-Fi訊號來做定位依據，提高整體的定位成功率，並嘗試利用Wi-Fi定位與GPS協同運作來提高整體精度。Wi-Fi定位採用訊號紋辨識法，欲使用訊號紋辨識法必先建立Wi-Fi訊號資料庫，包含地理坐標與對應的訊號來源與強度分布。實驗區為政治大學山下校區綜合院館四周面積約1.76公頃區域，模擬被遮蔽狀況下的GPS導航定位精度，配合Wi-Fi定位來輔助GPS定位結果。結果顯示利用兩種定位系統，可使平面平均定位誤差小於10公尺，高程平均定位誤差小於1.5公尺。 / The positioning accuracy is an important issue for Location-Based Service (LBS). LBS has many products, and its applications are usually based on Global Positioning System (GPS), because GPS navigation has been very mature. GPS has a typical outdoor positioning error of up to 15 meters for civilian users. Hence it has become a viable method for civilian to carry out coarse positioning. However, it has its shortcomings. GPS is available only in outdoors with a clear view of the sky. Since Wi-Fi (Wireless Fidelity) has become another positioning technology which is capable of performing positioning in indoor environments and urban canyons. Wi-Fi positioning is using fingerprinting in this study. This study is desirable to integrate GPS and Wi-Fi positioning technologies for ubiquitous positioning. The related issues of Wi-Fi/GPS technologies, such as database quality, analysis of algorithms, and database processing procedures were studied. Test data sets from National Chengchi University (NCCU) campus will be used to test the proposed algorithms. By using those two positioning system , it is revealed that the positioning accuracy made at the test sites resulted that the 2D coordinate average error is less than 10 meters, elevation positioning average error is less than 1.5 meters.