Abstract: The differentiation of islands and rocks is a complex issue in the field of the law of the sea. In recent years,there have been fierce debates in academic circles regarding the definition of islands and rocks,the relationship between islands and rocks,the specific implications of sustaining human habitation and sustaining economic life of their own,and the relationship between the two,but no consensus has been reached so far. In practice,in order to maximize their own interests,unified standards for the identification of islands and rocks have not been formed among countries. International judicial or arbitration institutions tend to consider the effects of islands and rocks in maritime delimitation to avoid this intractable issue. The tribunal's award in the ‘South China Sea Arbitration’ initiated by the Philippines interpreted this issue comprehensively,but there are many problems with the tribunal's decision. It is not the authoritative interpretation of the islands and rocks. The revision and refinement of the regime of islands under UNCLOS is the fundamental method to solve this problem; the parties to the dispute can also avoid this argument by exploring the effects of the islands and rocks in maritime delimitation; for the continental countries which have mid-ocean archipelagos baseline delimitation problems,it is advisable to further clarify the related theory and practice and to promote legal certainty.