This article has an aim to study what kind of housing system our ancestors lived with during the Yi-Dynasty by analyzing the house-plan of upper-class society of that period since the house of lower-class was very insignificant as it has always been while the house of upper-class represented the period. With this study we can clearly see how we ought to go in the right direction toward the development of our Korean genuine housing by renovating and renewing those unreasonable points in our traditional housing system. It is firmly believed that we should-keep our own unique traditional lovely housing system for being destroyed by the whirl-wind of modernization and the demand of rationalism and efficiency-centered idea of the western mind. From this view point we think it is very urgent to see this matter correctly and find out the real way how we should do in order to keep our own good things for ourselves and make them preserved. This essay is divided into three parts as follows : 1. Thoughts on selecting the good housing area. 2. The aspect of housing reflected upon composing the house-plan. 3. The characteristic sentiments reflected upon the interior construction and decoration. We can find several characteristic points in the housing system of the Yi-Dynasty as follows : 1. In Korea, the thought of natural geography (Poongsu-seul), apart fro scientific view, which seems rather superstitious to us, modern young people, has been highly recommended by the people of our country from old days connected with the prosperity of our life. They also neglected about the social circumstances such as, market, transportation, and education, which are now considered as very important. They only put their concern on this natural environment which they called Poongsu. 2. In construction of house-plan, the house was not built for living with reasonable convenience, but for showing prestige of the upper-class people reflecting its social organization under the feudalism of the period. Furthermore, the most of the housework was done actually by those servants and maids of the house, and not the family themselves. The only concern for the upper-class people was to show off their authority, and so this sense of authority was revealed in the housing as well. 3. Both the outside appearance of the house and the interior decoration or the furniture are all very artistic and lovely. They were so refined and beautiful with their delicate taste which truly seem against our modern rationalism and uniformity.