歐洲聯盟整合至今，在其現行歐盟法等基礎條約中，對權限缺乏清楚與明確的劃分依據。歐體條約與歐盟條約僅有廣泛規範權限之授權原則，條款中並無明文規範權限之劃分與種類。歐盟與會員國之權限劃分，往往處於一種變動與不確定性，同時也產生許多爭議。歐盟爲解決前述之缺失，2001年12月在布魯塞爾召開之拉肯歐洲高峰會上，歐盟權限的劃分與限制便成爲探討歐鹽改革與制憲議題所提出的重點之一。在經歷歐盟內部一年半之討論與改革後，2003年7月18日所公佈的歐盟憲法條約草案中，將歐盟與會員國權限之規範明訂於憲草第I-9~I-17條中，此舉便成爲首次將歐盟與會員國間權限類別明文規範於條約之先例。針對前述版本，各會員國經協商談判後終於在2004年6月25日達成一致性之決議。歐盟25個會員國之領袖於2004年10月29日齊聚於羅馬，共同簽署了『建立歐洲之憲法條約』，促成了歐洲憲法的誕生。此份由會員國共同簽署之歐盟憲法條約已將『草案』等字眼刪除，並彙整成一新版本，將聯盟與會員國權限之規範明訂於憲法條約第I-11~I-8條。本篇將針對歐盟與會員國間垂直權限劃分此一議題，就現行條約之規定及未來憲法條約之內容進行探討，觀察權限劃分之沿革及發展。

After a long-term integration of the European Union, there sill lacks any clear and precise principles in current Treaties for the division of competences between EC/EU and its member states. There exists only an extensive principle of conferral in Treaty establishing the European Community and Treaty on European Union, but still lacks provisions regulating division and categories of competences. Therefore, principle of competence division inevitably stays in a changeable and unsure situation, as well as provokes a great deal of controversies. With a view to solving the above-mentioned problems, "Limits and division of Competences" becomes one of the essential issues for EU reforms in the Laeken European Council of December 2001. After debates in the European Convention, Draft Articles I-9 to I-17, regulating competences between EU and its member states, are proclaimed in the Draft Treaty establishing a Constitution for Europe adopted by the European Convention in June 2003. This is the first time and a pioneering work to put these provisions in the Treaty. After 18-month negotiations, member states finally reached a compromise, and make some revisions of the Draft Treaty establishing a Constitution for Europe. In October 29th 2004 the Treaty establishing a Constitution for Europe has been signed by the EU member states. In this version, Article I-11 to I-18 regulate the competences of the EU and its member states. This thesis will draw an analysis in this issue, the Division of Competences between EC/EU and its member states, as well as discussing its evolution and future development.