Young children health problem were reported in a Korean daycare centers and supposedly attributed to the presence of air pollutants. This study attempted to characteristics of carbonyl compounds exposure of young children at the indoor spaces. The characteristics associated with the major indoor pollutants exposure included seasonal variation, and room location inside a daycare centers. As the results of investigation for daycare centers, the mean concentrations of formaldehyde, acetone, and acetaldehyde in daycare centers were 38.3㎍/m3, 33.9㎍/m3, 13.6㎍/m3, respectively. The indoor space carbonyl compounds concentrations were both higher for the summer than for the other seasons. The temperature and relative humidity measured along with the volatile organics measurements temperature and relative humidity increase volatile organics levels. This last suggestion is further supported by the correlations of the carbonyl compounds measured for daycare centers. Significant correlations between carbonyl compounds were exhibited for both the temperature and humidity, with at least p<0.05. The concentrations of formaldehyde in classroom were higher than lobby or dining room. Therefore, controlling indoor air pollutants exposure in daycare center should be given a high priority so as to minimize the potential sources of air pollutants in indoor space. Keywords : Indoor air pollutants, Daycare centers, Carbonyl compounds, Season