After an important construction work in Chosun dynasty, the appropriate government made out the building specification as it called 營建儀軌. They are recorded about variety matters as the appointed days, various official documents, managers and craftsmen, etc.. Sometimes we can see the attached pictures about some building or furniture. specifications in Chosun dynasty about the unit of materials and history of each terms. The results are as followings: (1) The interior materials are classified to several units such as Gai(箇;the unit of square lumber or log), Rip(立;the unit of plates), Boo(部;the unit of assembled materials), etc.. (2) The terms are defined and enlightened how to use and how to change. Particularly, the terms are different positively in constituent units of wooden floor. So, it is expected to continuant study.