英國於 2016 年 6 月 23 日舉行全國性公投，脫歐派以 51.9%勝出，再於 2017 年 3 月 29 日啟動《歐洲聯盟條約》第 50 條脫歐程序，意味英國通知後的兩年內脫離歐盟。英國脫歐將對英國與歐盟帶來重大深遠之影響，英歐未來關係很大程度將取決於脫歐談判之結果，包括脫歐條件、過渡機制以及雙邊協定等安排。本文以英國脫歐對歐盟之影響為研究對象，探討英國脫歐對歐盟預算、經貿、歐洲整合及對外關係等方面之潛在影響。本文建議英國與歐盟應從事理性談判，架構出一項有助於未來合作關係的協定，以確保英國有秩序的脫歐，並維持歐洲的穩定，創造英歐雙贏的結果。

A national referendum was held in the UK on 23 June 2016, with the result of a 51.9% vote to exit the EU. On 29 March 2017, the UK triggered the Article 50 procedure which will lead to Brexit in two years. Brexit poses a big challenge for both the UK and the EU. Future UK-EU relationship will mainly be decided by the results of the Brexit negotiations, in terms of its exit arrangements, transitional mechanisms, bilateral agreements, etc. This paper focuses on the impact of Brexit on the EU, particularly on the EU’s budget, economy and trade, European integration, and the EU's external relations. It is expected that the UK and the EU will conduct rational negotiations and conclude a cooperative agreement on their future relationship, ensuring an orderly Brexit and bringing a win-win result for both the UK and the EU.