國際司法機構在其大陸架劃界相關的判決中，曾主張過一些重要的概念，如：陸支配海原則、自然延伸、衡平原則、相關狀況以及共同大陸架的劃界原則。本文的目的在於檢討這些原則以及藉此重新釐清國際習慣法中大陸架劃界制度。本文亦將探討在國際習慣法或國際實踐案例中是否存有單一分界線的規定。此外，本文亦探討國際司法機構在處理相關國家的劃界爭議時，發展出一套劃定分界線的步驟。由於每個劃界案中的事實皆是獨一無二的，相關狀況得基於其不同的性質而為歸類，例如：地理、法律、安全、經濟、環境資源及社會狀況等等，國際習慣法不可能鉅細靡遺的明確規範相關狀況為何，因此，本文所歸納出之劃界步驟，雖尚非形成國際習慣法，但應仍具有國際實踐上的參考價值。

The international judicial institutes have propounded in their decisions concerning the delimitation of continental shelf some fundamental concepts, namely natural prolongation,the delimitation of common continental shelf, equitable principles, relevant circumstances and the maxim that the land dominates the sea. The purpose of this article is to examine these concepts closely and by doing so to renew the understanding of the regime of the delimitation of continental shelf in customary international law. This article will also examine the issue of whether there exists in customary international law or national practice a rule of so-called single delimitation boundary. This article discussion on the principles of international judicial institutions. Because each case has its own characteristics, such as geographic, legal, security,economic, Environmental Resoures and social conditions,etc. so customary international law can not regulate in detail various situations. Thus concludes the steps in this article, still has a reference value of international practices.