The purpose of this thesis is to study on the source, the introductive process and the phenomenon of the regional tendency into Korean modern interior design. To achieve the purpose of this study, the methods and contents are as follows : 1. Explaining the regionalism in the architecture as the source of the regional tendency. 2. Explaining the introductive process of the regional tendency in Korean modern interior design.. For that, 1)Explaining the traditional expression, the leo-corbusian expression and the organic expression with nature in Korean contemporary architecture 2)Explaining the vernacular expression and the abstract expression in Korean modern art 3. Studying the regional tendency in Korean modern interior design For that, 1)Studying the expression of Korean traditionality 2)Studying the expression of the vernacular 3)Studying the expression of the environmental affinity By theme methods and contents, we will study the introduction of the regional tendency into Korean modern interior design.