China’s 21st-Century Maritime Silk Road Initiative urges the protection of underwater cultural heritage on the Maritime Silk Road, which demands China’s effort as much as that of international community. The Convention on the Protection of the Underwater Cultural Heritage (unesco Convention) provides an international legal framework for China to protect underwater cultural heritage and facilitate cooperation with other State Parties. China’s concerns over ratifying the unesco Convention mainly relate to its jurisdiction, ownership and international obligations on the issue, which can be solved with the basic principles and a revision of Chinese laws. China’s ratification will ensure the international protection of underwater cultural heritage on the Maritime Silk Road; and more importantly, it will provide an opportunity for the joint development in the South China Sea, thus breaking the bottleneck of the Maritime Silk Road Initiative. Therefore, China should ratify the unesco Convention.