The purpose of this study is to identify the characteristics of building transformation from Poongkyung Palace and Hwasoeng Palace to Hospital in the Japanese occupation with architectural drawings. In the relation between building and courtyard, the siteplan transformation from the Door-hall system(門堂制) to the pavilion hospital system caused that the spatial hierarchy was rearranged and whole facilities were divided into exterior and interior. And in the view of interior composition, whole spaces were subdivided small rooms and they were integrated by indoor corridors which classified according to the side size. Further more, traditional heating system and built-in lavatory were unitized within four columns and doors replaced traditional paper windows to make independence of each room to another.
