In the old time of China, the famous officer Zheng He was appointed to explore the new areas of the world by sailing a big ship. This was an important event in the history, he opened the new world for Chinese people and he was much earlier than other explorers. In order to in honor of the great movement of Zheng He, Chinese government agreed to revise the day March 17th as the International Navigation Day. Nowadays, the meaning of this day has gone much further, it gives applause to the international friendship between countries in the navigation. The countries desire to seek more cooperation in these sea areas and promote the economy together. China plays the important role in maintaining the peaceful sea environment, and the policemen deserve the biggest praise.