In the Cold War era, educational broadcasting became a new technological instrument in less industrialized countries, to enhance the quality of education. Specifically, the use of mass media in classrooms was starting to be considered a modernized way for developing the educational system in less industrialized regions. This study argues that educational broadcasting in less industrialized areas, including South Korea, reveals the effects of Cold War politics in educational development in many countries. Through the concept of localized modernization, this study highlights American educational aid programs in establishing an educational broadcasting system in a foreign country and its effects on changing the entire educational system focusing on the case of South Korea. By investigating various archival sources published by governmental agencies, international organizations, and local governments, this dissertation reveals how some less industrialized regions sought to change their educational system by using a new modern technology, educational broadcasting, and how a new educational idea—that the use of mass media in school instruction can change the entire educational system—influenced, changed, and was adopted in these areas. Although the U.S. Agency for International Development introduced mass media to modernize education, this study shows how local people adapted a new educational broadcasting system to their own purposes and unique circumstances. Korean policymakers and educators agreed with some parts of the U.S. recommended system, but used them for their own needs. The educational broadcasting system in Korea proceeded differently from the U.S. recommended system. The author thus argues that the case of educational broadcasting in South Korea is an example of how local countries constructed their own educational broadcasting systems, how individual countries adapted U.S. systems during the Cold War era to their own needs, and how the localization of the modernization process can be an alternative lens for an overview of the historical pathway of U.S. educational aid projects in the Cold War era.