From the beginning of the 21st century, Japan has strengthened national marine legislation to implement new marine strategy, especially in the aspects of marine policy, marine safety, marine territory and marine resources. To Japan, Japan’s new marine legislation has a positive effect on dealing with Diaoyu Island problems and the delimitation on the East China Sea with China. To China, the new marine legislation has a negative effect on developing China’s marine strategic space, maintaining ocean passage safety and solving marine disputes peacefully. Japan’s marine legislation provides us some revelations: (1)Formulate the new century national oceanic strategy, to adapt to new international situation; (2) Improve the system on comprehensive approach to ocean problems, so as to command national marine affairs; (3) Further strengthen talent training and marine science and technology investment, to realize sustainable development of China’s marine economy ; (4) Strengthen maritime law enforcement reserves, to maintain China’s marine rights and interests effectively; (5) Strengthen marine education to enhance people’s marine awareness.