The 1940s and 1950s were a period of both great chaos and great change for the Jeju region. The April 3rd Incident of 1948 and the ensuing Korean War, beginning in 1950, were events that altered society greatly, but very little research has been done on how these events impacted residential architecture. Furthermore, as the related sources and materials from this period are somewhat lacking, there appears to be a need to systematically organize these sources and materials to help us better understand the impact of these events on residential architecture. This research aims to serve as a basis for the conservation and utilization of cultural assets by analyzing the historical sites related to the April 3rd Incident and the distribution of residential architecture from that period. The research was done through analyzing original source documents and by visiting relevant sites. First, for the original source documents, we selected newspaper articles from media organizations and periodicals from administrative organizations that what we deemed to be relatively objective and the most factual. Second, for the on-site visits, we surveyed some still-existing residential architecture and analyzed the testimonies of residents who lived in those areas. Analyses of residential architecture typically include design, space, material, composition and facilities, however our analysis focused primarily on design and space. Based on sources from the April 3rd Incident, we analyzed the residential architecture as being characterized by damage spatial distribution, especially in areas where the leaders of the suppression were concentrated. The regional distribution of lost villages, places of refuge, massacre sites, and fortresses designed primarily for defensive purposes was interesting, but we interpret it to be a reflection of the strategy of suppression by the punitive force. In addition, in order to rebuild the society after the Korean war of the 1950s, refugee camps were constructed and destroyed homes were rebuilt. With the exception of temporary fortress built primarily for defensive purposes,these were built with materials that were totally different from traditional Jeju architecture, such as cement and wood. The most interesting differences, however, were those of design and space composition. This research was limited by the fact that we did not analyze the specific years of completion or the size of the structures, and thus there still remains a need for a survey of diverse source materials and research.