Western sea power theories are of a strong maritime hegemony color. China’s sea power is a unity of marine sovereignty, sea rights and command of the sea, characterized by self-defense and limitation. Because of the absence of marine clause in Chinese Constitution, the legal protection of sea power in China has defects like lack of constitutional concern, lag of relative legislation and unbalanced system. The constitutional protection of sea power is necessary, which would provide a clear basis for solving island and maritime disputes and enhancing the legitimacy of the marine law enforcement. The report delivered at the 18th CPC National Congress has created the opportunity of putting marine clause incorporated into the Constitution. The constitutional path of sea power will provide the direct protection by marine clause and indirect protection by authorized common law.