美國與歐盟在航空產業的補貼爭議已有數十年之久，雙方互相指控對方補貼其國內民用航空器製造業，此一爭議雖經雙方談判協商，但終究談判破裂而進入世界貿易組織（WTO）爭端解決機構，成為WTO歷史上涉案金額最大的一次貿易糾紛案。雖然美國與歐盟就航空器補貼爭議相互於WTO下提出訴訟，總計成立了四個爭端案件，在如此複雜的情況下，目前僅歐盟航空補貼案（DS316）已進入至言詞辯論程序，其他爭議案均未進入實質審理程序，尚無資料可得分析，因此僅就DS316一案而為討論。 / 在該案中，美方指控歐盟以開發補助、基礎設施、研發技術補助等措施為空中巴士進行補貼，提升空中巴士之市場競爭力，對美國波音公司產生不良影響。上述措施是否違反WTO規定，著實進一步分析探討之必要，因此本文將介紹補貼及民用航空器的相關規定，由SCM協定下之補貼構成要件－政府財務補助、利益及特定性之要件，判斷歐盟是否構成補貼，而其中尚須檢驗美國與歐盟首次書狀中論點之合理性、考量過去小組類似判斷之見解與顧及1992年美歐航空器的雙邊協定，最後嘗試預測未來小組判斷中，對補貼之構成與否及其法律效果之意見。 / Subsidy dispute of aviation between the US and EU has been lasting over the past decades. Both sides accused each other of subsidizing domestic civil aircraft industry. In spite of having made efforts to solve the trade clash through negotiations, they eventually took the subsidy dispute before Dispute Settlement Body of the World Trade Organization（WTO） after the negotiations had failed. In the biggest case ever to come before WTO, US and EU separately filed legal complaints against each other at the WTO, which set up four dispute cases. However, except the oral arguments were held in the European Communities-Measures Affecting Trade in Large Civil Aircraft（DS316）, the three other cases have not yet entered into substantial procedures. Therefore, this thesis intends to focus on the DS316 due to no related data available to analyze the rest of the cases. / In DS316, the US argued that EU subsidized Airbus by way of such measures as Launch Aid, Infrastructure & Regional Aid and Research & Technology to improve Airbus’s competitiveness in the aviation market and put its US rival Boeing at disadvantage. Given that whether the EU subsides are against the trade rules of the WTO needs further studies, this thesis would like to interpret related rules which regulate subsidy and civil aircraft industry. It would also like to decide if the EU involved in subsidizing by examining the constitutive requirements of subsidy under the Agreement on Subsidies and Countervailing Measures（SCM agreement）including financial contribution, benefit and specificity. This thesis will review the rationality of arguments in the first written submissions both by the US and EU, and then deliberate the opinions of similar decisions from the WTO panel in the past as well as take into account the Agreement between the European Economic Community and the Government of the United States of America concerning the Application of the GATT Agreement on Trade in Civil Aircraft on Trade in Large Civil Aircraft in 1992. Finally, this article tries to forecast the opinions about what is regarded as subsidy and the related legal effects in future decisions by the WTO panel.