In response to growing needs for developing Korean Language teacher expertise and diverse Korean language learners, appropriate retraining programs are the key to successful Korean language education. The purpose of this study is to specify and guide program contents designed to retrain Korean language teachers for multicultural families. For this goal, a questionnaire survey was adopted as a main research tool and literatures on national and international teacher training were reviewed. One hundred thirteen teachers who attended multicultural teacher training programs were surveyed and their responses were analyzed in quantitative and qualitative ways. The results of the study showed that the factors affecting the programs are as follows: 1) In-depth Korean pedagogical content knowledge, 2) various, practical practices in Korean teaching methods, 3) developing and utilizing Korean teaching materials, 4) comprehension on assessment system, 5) understanding the uniqueness of immigrant students, 6) teachingreflection and sharing teaching moments, 7) developing strategy and direction for cultural pedagogy. Therefore, this study may shed light on shaping teaching expertise to build teacher development.