台灣與日本均為四面環海的島國，由於一衣帶水、地緣相近之故，無論在歷史、地理、經貿和集體安全各方面，雙邊關係往來皆甚頻繁密切。惟自20世紀90年代以降，受到全球化海權運動的蓬勃開展與《聯合國海洋法公約》公佈施行的雙重影響，連帶使得台日雙方在相鄰海域的往來互動逐漸成為觀察台日關係安定良否的重要指標。尤其是在既有的釣魚台群島主權歸屬問題之外，近來復因漁船越界糾紛與大陸棚資源開採摩擦而導致尖銳的海權爭議，愈發使得台日關係的維繫不得不面臨種種前所未有的嚴酷考驗。本文之目的，即在藉由東海暫定執法線為例，首先探討台日海權爭議的時空背景，以敘明歧見問題之所在。其次透過海域劃界的角力攻防，引申海洋法理在系爭案例之相關規範，以資釐清台日爭議的是非脈絡。最後則總結台灣在處理對日關係議題上的盲點，並指出今後台灣在迎向海洋世紀潮流中應有的認知與作為，俾有助於重建台日關係之良性互動。

Both Taiwan and Japan are surrounded by the sea. In geography, they are quite near. Their relationships in such areas as history, culture, trade, and so on are very close. Their close contacts in the sea area, however, have become important issues. For example the territorial dispute surrounding the Diaoyutais, the dispute over fishery, there are many other debates between both sides in the sea area. This paper focuses on the Provisional Jurisdictional Line in the East China Sea, and intends to analyze the debates on sea power between Japan and Taiwan. Firstly, this paper explains both the viewpoints of Japan and Taiwan in sea power. Secondly, it introduces the judicial decisions on the law of the sea and explains the debates between Japan and Taiwan in the sea area. Thirdly, it illustrates the blind points in the relationships between Japan and Taiwan and studies the solutions