Abstract: Under certain circumstances, the drafters of an international treaty may intend to give a treaty term an evolving meaning in order to adapt to new developments after the adoption of the treaty. So as to give effect to such an intention, certain treaty terms should be interpreted evolutively. This kind of treaty interpretation is called evolutionary interpretation. After delineating the nature, the legal basis of evolutionary interpretation and the elements to be considered when determining the relevancy of evolutionary interpretation, the paper concludes that certain treaty terms under UNCLOS can be or should be interpreted evolutively. One example is the term “marine scientific research”. By interpreting the meaning of this term evolotively, UNCLOS and its provisions concerning marine scientific research can be applied to the context of the BBNJ negotiations, and provide legal options for solving a “new problem”, namely the access and benefit sharing regime for marine genetic resources in areas beyond national jurisdiction. At the same time, evolutionary interpretation may also have a role to play in interpreting certain provisions of the to-be-adopted BBNJ instrument. Based on the elements to be considered when determining the relevance of evolutionary interpretation, the paper analyzes the elements of the BBNJ negotiations that potentially affect the interpretation of the provisions under the BBNJ instrument.