This research marks the initial step toward the research on Korean language education for Christian missionaries in the colonial period. There have been some discussions on Korean language education for Christian missionaries in the field of History of Korean Language Education. Yet these do not go beyond mere conjecture, and there have not been any study which is supported by historical evidence. By using a meeting record, Annual Meeting of the Federal Council Protestant Evangelical Missions and a journal, The Korea Mission Field, both published by the Federal Council Protestant Evangelical Missions, this research managed to show that there in fact was a Korean "Language School" at least between 1920 and 1936. With the same materials, there search also made clear the educational system of the "Language School" and its educational curriculum, which under went changes five times, as well as the text books used and their transformation. Korean language education of this time is considered to have been terminated after 1942, when the Pacific War occurred and missionaries were chased away from Korean Peninsula. However, it is considered that after the liberation Korean language education was resumed for the missionaries returned to, and newly coming to, Korean Peninsula. It is also probable that this may have some connection with the establishment of Yonsei University Korean Language Institute, where the so-called "modern" Korean language education started. Further research is expected to be done on this historical continuity.