中共在經濟崛起後，累積巨大國力，並積極發展並鞏固海權。各項海洋法制已趨完備，持續對於東海及南海各項聲索。日本政府於2013年購買釣漁臺列嶼收歸國有，中共隨即公布東海防空識別區，影響周邊空域交通及區域安全。然防空識別區之法律定性究竟如何，影響中共於東海防空識別區實施管制措施是否合法。本文爰由主權在空域行使之條約法及習慣法基礎出發，探究防空識別區之性質，以及沿海國應有之權限。並分析東海防空識別區劃設之背景及其對區域之影響。

Mainland China has been developing and maintaining its sea power after its economy is booming. Its maritime legal structure has been established, and maritime claims vis-a-vis sovereignty in the East China Sea and South China Sea are continuously made. After Senkaku Islands were bought by Japanese government in 2013, Mainland China implemented its Air Defense Identification Zone (ADIZ) in the East China Sea. However, the legal status of ADIZ affects the measures that a costal state could adopt against foreign aircrafts flying in that air space. This article explored the legal status of ADIZ from the perspectives of international convention laws and customary law to conclude the jurisdiction and sovereignty that a coastal state may claim in the ADIZ. Furthermore, this article discussed the backgrounds of why the East China Sea ADIZ was established and its impact on regional security.