Abstract: Ocean acidification has become the vital environment issue that we must confront in the 21st century, and its impact on ocean ecosystem is now hard to be accurately estimated. Ocean acidification is a natural process in earth system under the strong anthropogenic influence, and a major global environmental problem related to the global warming issue. It is one of the most threatening disasters to the ocean ecosystem and its impacts on ocean health are gradually manifested. Therefore, it is one of the great interests of the countries adjacent to oceans and related international organizations of the world. The United States, the European Union and Britain, etc. have one after another formulated their plans for ocean acidification studies, and countermeasures are also studied in response to ocean acidification and for marine eco-environmental protection. The paper will briefly summarize the findings of international ocean acidification studies in the past decade.