This study was conducted on the premise that plan types of the public residential houses proposed after the 1945 implicatively showed the developing process of the modern housing. The formal characteristics created through the developing process were analyzed in Micro-Historically. Moreover, by providing a new viewpoint on the changes of the residential houses that occurred around 1945, we tried to provide the fundamental research background for the research on the developing processes of the future housing cultures. The research pursued mainly on the major spaces that became the modern change indices of housing plan changes from the traditional housings in 1940s to the modern housings such as the master bedrooms(An-Bang), kitchen, the main floored-space(Maru), and the secondary bedroom (Kune-Bang). The major experimental subjects are the 87 public residential plan types designed and supplied by the Korea Housing Cooperation in between 1945 and 1970. The study synthesized the developing process of the public residential houses from the traditional residential houses in 1940s through modern situation and intrusion of foreign housing cultures. Following results were derived from the study: First, various and experimental housing plan types had been proposed as public residential houses since 1945. Among them, the plan having the main floored-space(Maru) were the representative type of public residential houses and various series of houses were constructed based on this type. Second, the main floored-space(Maru) type had continued building connection order of the R-M-R that were used in the traditional houses. On the other hand, with decomposition of connecting ring between the main floored-space(Maru) and the kitchen, rationalization of women circulations and introduction of family-centered spaces had been resolved the demands of modern society. It had greate effect on settlement of the current double-row Maru plan type. Third, in Korea most of plan types for the public residential houses were proposed in between 1945 and 1965. Forth, the location of kitchen and relation between Maru and the master bedroom were arranged visually on the corner and center of the rear row with the micro change characteristics of the public residential houses. In this process, the front row was similar with traditional residential houses but the rear row was differentiated and developed with expansion of Maru and Ondol rooms, increase of closet spaces, and introduction of kitchen that divided spaces for sleeping and eating.