東海位於中國大陸、日本及韓國之間，係由韓國、日本、中國大陸及台灣所包圍之「半封閉海」（semi-enclosed sea），其具有寬廣而平坦之大陸礁層。1969年「聯合國亞洲及遠東經濟委員會」（United Nations Economic Commission for Asia and Far East, UNECAFE）公布一份報告，指出東海大陸礁層蘊藏豐富的石油及天然氣。自此，東海主權權利歸屬開始成為周邊國家關注之議題，更引發中國大陸及日本對於東海天然資源開發活動之爭端。 中、日二國間對於東海大陸礁層劃界採取之原則不同，中國大陸主張「自然延伸原則」（principle of natural prolongation）及「衡平原則」（equitable principle），日本則主張「等距離線／等距離規則」（equidistance-line/median-line rule）。對此，本文將自國際法上有關海域劃界的基本原則、國際公約之相關規定、國際司法機構判決理由與各國實踐，分析中、日雙方對於東海大陸礁層劃界之主張。 截至目前為止，中、日二國針對東海問題已進行十一輪雙邊協商，足以凸顯兩國對於大陸礁層劃界爭端獲得最終解決的重視與急迫性。是以，本文將說明中日雙方於歷次協商中所獲致之具體成果，藉此推論出 中、日雙方所達成的共識與所遭遇的困境，並將於文末分析雙方應透過何種模式解決東海問題。

The East China Sea where is surrounded by the People’s Republic of China (P.R.C.), the Republic of China (Taiwan), Japan and Korea is a semi-enclosed sea. On 1969, the United Nations Economic Commission for Asia and Far East (UNECAFE) published a research report, which pointed out that the continental shelf in the East China Sea is abounded with oil and natural gas. Since that time, neighboring states have been having disputes over the sovereign rights of the East China Sea, particularly the dispute over the exploration and exploitation of natural resources between the P.R.C. and Japan. The P.R.C. and Japan have always been taking conflicting positions on the delimitation of continental shelf in the East China Sea. As far as this issue is concerned, the P.R.C. claimed the principles of natural prolongation and equitable solution while Japan argued the equidistance-line/median-line rule. In this article, the two states’ viewpoints about the delimitation of continental shelf in the East China Sea from perspectives of general principles of maritime delimitation, provisions of relevant international treaties, judicial decisions and state practices will be examined. Moreover, during 2004 and 2007, the P.R.C. and Japan had convened eleven bilateral round-table talks named “Consultations on the Issues of the East China Sea,” which highlighted the two states’ desirability of definite settlement of the dispute over the delimitation of continental shelf in the East China Sea. Accordingly, this article will elaborate specific outcomes achieved by the P.R.C. and Japan through bilateral consultations so as to conclude the consensus the two states have made and the difficulties the two states have faced. In the end of this article, it will also be analyzed how the disputes of the East China Sea between the two states could be finally resolved from the perspective of international law.