The purpose of this study is to analyze and explain the formation and character of presbyterian missionary architecture in Andong area from 1900 to 1945, which we may call "the modem architecture of Korea". I have surveyed and analyzed the 26 buildings. and so, the major findings of this study are as follows. Firstly, the phase of building is 1) buy the existing Korean traditional building and lot-a thatch roofed house. 2) modify the existing Korean traditional building-a thatch and tile roofed hose. 3) build the Korean style building-a thatch and tile roofed building. 4) build the Western style Building-a timber structured and zinc roofed building. 5) build the Western style Building- a masonry structured and zinc(or tile)roofed building. Secondly, the character of building is 1) In the Korean traditional building, the missionaries change the function for their purpose-office, church, school, hospital. they modify the existing Korean timber frame construction by introducing the material-brick, plaster, glass, Japanese style timber etc .. they live in the Korean existing residential area. 2) In the Western style building, the missionaries build the house according to their life style. they build the timber structured building-church, and the masonry (brick or stone)structured building such as a house, church, school and dormitory, and hospital. their building located on the hill depart from the existing Korean residential area.