The indoor air quality of residences has been regulated by designating recommended standard levels of pollutants for newly built apartments. But as of yet, no related guideline has been established for dwellings that are already occupied. From a sociological viewpoint, the gap between the rich and poor has been gradually increasing with economic development, and this has extended to the diversification of house types and living environments. Specifically, people who have the lowest income levels may live in temporary houses such as vinyl greenhouses and shanty houses, and their living environment is mostly inadequate as a result. In this study, we surveyed the indoor air quality in normal and socially vulnerable houses after the occupation stage and tried to figure out the main factors influencing indoor air quality. Airborne fungi are detected more frequently in lower living standard houses. Put another way, the concentration of airborne bacteria and the volatile organic compound levels are much higher than in normal dwellings. Keywords : Indoor air pollutants, Indoor air quality, Social vulnerable houses