This paper traces the source and the basic idea of the concept of "Nihon-shumi (Japan-taste)". Chuta Itoh dealt with architectural style in his graduation thesis of the 25th year of Meiji. He discussed the connection between architectural style and taste, and defined architectural style by using the concept of "national taste" in it. Itoh quoted the word "national taste" which Fenollosa and others had used in their books, and conceptualized it by making use of the concept of taste in the field of psychology and aesthetics. The concept of "Nihon-shumi" originated from this Itoh's idea, and was founded on the basis of the idea which defined architectural style in connection with taste.