Researches on the pit dwellings in the Joseon Dynasty era have been constantly conducted in the archeology field since the beginning of the 2000s. Most of the related researches in the past have been on the classification and chronological record of dwelling types in archeology, but architectural researches on the dwelling history that is connected from the prehistoric age to the Joseon Dynasty era are insufficient. There are no big differences between the excavated pit dwellings of the Joseon Dynasty era and those of the prehistoric age, so pit dwellings were considered to have been used as dwellings for common people until the Joseon dynasty era. This fact is confirmed by the frequency and density of pit dwellings. In this research, what space composition of the pit dwellings that are equipped with the Korean floor heating system is shown according to the plan types was examined and the development and transition process from pit dwellings to Folk houses were analyzed and their correlations with the Folk houses of the Joseon Dynasty era were examined. The Folk house form did not start with the form of the house on the ground but originate from the introduction of Ondol, the Korean floor heating system, to pit dwellings. As the Korean floor heating system is used, the room and kitchen space are composed in the pit dwelling, and the kitchen is expanded to the one that separates the fireplace for cooking to avoid heating that is unnecessary for the summer season. As the size of the dwelling was getting bigger, the division of the space is made by the pillars that support the interior space. Also, the dwelling is expanded into a single row house and a double row house according to the progress direction of Ondol. In other words, the pit dwellings in the Joseon Dynasty era develops with making up diverse floors through the combination and expansion of Ondol and kitchen according to the dweller’s convenience and life style and surrounding environment. This research is significant in the sense that it helps understand the formation and development process of our traditional Folk houses and fills the gap between the pit dwellings, which have been dealt with inadequately, and traditional Folk houses in the Korean dwelling history.