自1984年鐵路地下化以來，地下街漸成為國內普遍的都市設施，至今台北都會區亦已開發了八處地下街。而近年來有關地下街之研究多在強調經營管理面的重要性，將地下街視為重要都市商業空間的延伸，特別是在像台北這樣的商業密集型都市中，更認為經營地下街的目的在於創造巨大的商機，卻反而忽略了地下街規劃設計之原意及功能。鑑於地下街主要係銜接大眾運輸場站的通行空間，在交通功能外，兼具商業及防災等功能的複雜特殊場域。而如何有系統地診斷現況地下街規劃設計面之課題，乃為本文之研究重點。 基此，本研究首先回顧國內外有關人行空間、商業空間以及地下街之文獻研究，採以模糊德爾菲法（Fuzzy Delphi Method，FDM）進行評估因子篩選，整合多位專家學者建議與互動結果，建立包括交通順暢、防災保全與商業環境等三項層面之評估架構；再透過分析網路程序法(Analytic Network Process，ANP)，在考量各項評估因子間交互關係的前提下，彙整專家群體決策求取各項評估準則之權重值，完成「地下街空間規劃最適評估架構」之建立，其中發現專家群體首重「交通順暢」與「防災保全」兩層面，反視「商業環境」為地下街發展之附屬功能。 最後則以該評估架構為基礎，實地運用於現況地下街之檢討，針對台北市站前地下街與東區地下街進行實證分析，歸納出目前地下街所面臨之課題並提出相關具體建議。評估結果顯示，站前地下街於交通順暢與商業環境層面之表現皆不如東區地下街，得師法東區地下街之空間規劃設計進行加強；而在權重值較高的防災保全層面，此兩條地下街之因應手段皆有所不足，亟待相關單位進行改善。據此本研究除提出相關規劃、管理手段加以解決交通與商業環境面課題外，更強調透過疏散引導計畫研擬、防災管理系統整合、民眾防救災知識教育等手段改善現況防災保全之欠缺；進而建議相關單位得盡速建立一套專責法規範進行把關，藉以維護地下街建設之品質與安全。 / Since railway started to go underground in 1984, the underground streets have been emerging as popular city facilities in Taipei Megalopolis. Up to now, eight underground streets have been developed. In recent years, most researches about underground streets emphasize the importance of administration, and regard them as the extension of commercial space within cities, especially in the commerce-intensive cities such as Taipei. On the contrary, the underground streets’ original meaning and function of planning and design had been ignored. Owing to the complex and particular characteristics of these places, systematical diagnosis is needed to be discovered in spatial planning. For constructing an evaluation framework, this research reviews references related to pedestrian space, commercial space, and underground streets firstly. And, FDM (Fuzzy Delphi Method) method was utilized to extract proper impact criteria. To the evaluation framework, including three dimensions “traffic function”, “commercial environment”, and “disaster-prevention and security”, etc. Furthermore, ANP (Analytic Network Process) method was used to overcome the inter-correlation of each impact criteria for refining the evaluation framework and also generate the weight values. Both dimensions include “traffic function” and “disaster-prevention show high weight values as expected, contrarily regard “commercial environment” as accidental function of underground streets. Finally, based on this evaluation framework, user questionnaires were designed and surveyed in the Taipei Station Front Metro Mall and the East Metro Mall, for discovering the issues underground streets confront at present. Research results show that the planning of East Metro Mall is better than Taipei Station Front Metro Mall in the dimension of “traffic function” and“ commercial environment”. In the aspect of “disaster-prevention and security”, both these underground streets don’t have enough contingency ability, and should be improved immediately. According to the research findings, this study suggests some solutions for traffic function and commercial environment, and also emphasizes how to improve the planning of “disaster-prevention and security”. Moreover, related standards and guidelines for design and planning should be drawn up in related laws and regulations, in order to keep the quality and safety of underground streets’ space.