Due to the impact of the United Nations Convention on the Law of the Sea and other international practices in the law of the sea, an increasing number of Bilateral Investment Treaties (BIT) are incorporating “territorial defi nition clauses”to include water areas beyond a country’s territory in their scope of application. However, due to the fragmented nature of BIT, significant differences often exist in the territorial definition clauses of different BIT. Furthermore, there are substantial variations in the types and extent of sovereign rights and jurisdiction that states enjoy in different maritime zones, such as exclusive economic zones, continental shelves, high seas, regional waters, and other waters under national jurisdiction. This makes it necessary to assess on a case-by-case basis whether specifi c BIT are applicable in non-territorial waters and which specifi c maritime investments can be safeguarded. As a major player with signifi cant infl uence in both the international investment and the law of the sea domains, China should focus on the interconnected relationship between BIT and the law of the sea. Seizing the opportunity of their interaction, China should expedite the adaptation of more BIT for application in non-territorial waters and further expand the scope of BIT through the law of the sea practices. This pursuit aims to achieve common goals of safeguarding maritime investments and effectively participating in global ocean governance objectives.