The study, a historical analysis, focused on the influence of the United States on Korean secondary teacher training in the period from the liberation from Japan in 1945 to the year 1962, when the six years' service of the George Peabody College staff ended. In these years, three American groups played major roles in rebuilding the Korean system of education : they were teams of American educators affiliated respectively with the United States Army Military Government in Korea, the Unitarian Service Committee, and the George Peabody College for Teachers. Research questions addressed in the study dealt with the following problems: determining specific influences of American educational philosophy and methods on Korean educational programs: restructuring of goals and objectives of Korean secondary teacher training under the influence of the American educational system; and the relationships between American and Korean curricula and instructional methods in secondary school teacher training. Documents and reports- many of them unpublished -research studies, and significant theoretical and historical works in both the English and Korean languages were located and analyzed for their bearing on educational development in Korea during this time of direct American involvement, beginning with the crisis which ensued when 15.000 Japanese teachers and school administrators were repatricated, causing an acute shortage of trained educational personnel. The United States Army educators worked with the United Nations in Korea and set up the Teacher Training Center. They also instituted a lasting policy of Korean self-determination in educational reform and in the manner of implementation of democratic principles in the schools. Collectively, the American teams laid foundations for a new educational system, established libraries, conducted workshops and conferences nationally, updated teaching materials, introduced John Dewey’s philosophy and the methodology of progressive education, and sponsored study in the United States for Koreans. By 1962, it was clear that secondary school teacher training had generally received considerably less emphasis than the elementary level. Also, many inported American educational ideas and methods were imperfectly understood. Moreover, some approaches were being perceived as conflicting with Korean traditions and customs such as those relating to the authoritarian family structure.