The Analysis About International Trade Theory Evolution Logic

International trade theory discusses the cause of international trade,the distribution of the trade interests and the structure of international trade. International trade theory began from Adam·Smith as a special branch of modern economic theory. In his "the Wealth of Nations", Adam·Smith proposed absolute advantage theory, then David·Ricardo amended it and formed comparative advantage theory. Ohlin further improved comparative advantage theory and proposed factor endowments theory.The three theories are called traditional trade theory.From the end of World War II to 1980s, scientific and technological progress greatly promoted the development of international trade, the international market emerged many phenomenons that traditional trade theories can not explain such as technology products trade greatly increased;intra-industry trade developed. The new phenomenons sparked the reflection of traditional trade theory. Economists began to put forward some new theories to explain the increasingly complex international trade. Representative theories included the technology gap theory, product life cycle theory, new trade theory and so on.After 1980s, there was a new round of economic globalization.In the context of economic globalization, multinational corporations became the subject of trade. The field of international trade emerged trade within the product.Economic realities and changes in the pattern of trade promoted development of trade theory. Since 1980s the latest development trends of international trade theory is intra-products trade theory and new new trade theory.Although international trade theories are complicated, but their formations and developments have a certain regularity. Based on this kind of idea,according to the above method international trade theories are divided three phases in this paper. Through analysis of thought threads of international trade theory above stages from the perspective of the history of economic thought, I will explore the evolution internal logic of international trade theories from the following five aspects:practice motivation; theory motivation; trade interests;the assumptions and trade patterns,that can make us understand how international trade theories generate from real economic life and development, and how break through the limitations.Finally I will try predicting the development trend of international trade theory.The purpose is to make us see the essence through the phenomenon and more clearly understand the international trade theories and the reality of the international trade.