Contrary to the presumptions of conventional trade theory greatest part of the world trade consists of trade flows between developed countries and high proportion of trade flows is intra- industry rather than inter-industry as suggested by conventional trade theory under imperfect competition and scale economies has grown rapidly since the Iate 1970s. The aim of this study, therefore, to survey the central themes of recent international trade literature under imperfect competition and scale economies. However, this study aims to survey only some central themes of literature rather than being comprehensive. In the first part of the study, having briefly examined the preliminary studies emphasizing the importance of scale economies in international trade theory, early studies of new trade theories literature are analyzed. The main concern in the second part is the analysis of monopolistic competition trade theories within the context of reasons for trade, composition and volume of trade as well as the welfare impacts of trade In the third chapter, oligopolistic trade theories are discussed. Although the main emphasis of this study on the positive aspects of new trade theories, normative implications of the new trade theories are also highly important since it causes a theoretical debate due to its protectionist policy recommendations. For this purpose, policy implications of oligopolistic trade theories which is known as strategic trade policies are also examined in the study.