This paper makes a study on the trade dynamic of world soybeans from the aspects of trade volume,trade situation and international competitiveness. The results show that the world soybeans trade has kept a sound momentum of development,while its trade situation changed somewhat. The export market of world soybeans was monopolized by the United States only before the 1980 s. After that,it was monopolized by the United States,Brazil and Argentina together. China replaced Japan as the world soybeans biggest importer. The United States,Brazil and Argentina have strong international competitiveness...