日本在亞太地區的安全保障事務上已經扮演著無可取代的地位。當日本在修訂防衛政策時，防衛計畫大綱是規範日本防衛政策的基本架構，而防衛計畫大綱修訂前，日本政府會組成防衛問題懇談會，經過研討之後提出報告書，做為修訂防衛計畫大綱的主要參考，同時也提供防衛政策的理論依據。就日本防衛政策的訂定而言，防衛問題懇談會報告書具有前導性的關鍵功能。本文擬將歷屆報告書做為基本材料，針對報告書所提日本周邊安全環境的評估、日本的因應對策，以及美日安全保障關係的設定等，進行系統性地探討，期望掌握日本防衛政策與美日安全保障關係的發展脈絡，同時提供思考台灣安全保障時的參考。

Japan has been important and irreplaceable for Asia-Pacific security affairs. The basic structure of Japan's defense policy was greatly regulated by ”The Basis of Japan's Defense Policy.” Whenever The Basis of Japan's Defense Policy was amended, the reports which based on the discussion held by the Japanese government between experts and scholars, as said the ”Advisory Group on Defense Issues,” will be taken as an important reference. In this manner, Advisory Group on Defense Issues puts great influence on formulation of Japan's defense policy and development of U.S.-Japan security alliance.This article aims at the reports which published by Advisory Group on Defense Issues as basic research material, and systematically analyzes the assessments of the security environment Japan situated, Japan's response strategies, and the changes and developments U.S.-Japan security alliance. This article aims to understand the context of Japan's Defense Policy and U.S.-Japan security alliance; accordingly, may provide references for Taiwan's security.