||Due to the increasing need for the office supplies and the building materials, the emissions of various carbonyl compounds occur in the indoor environment. In this study, we investigated the emission characteristics of carbonyl compounds indoor environment with a major emphasis on formaldehyde, acetaldehyde, and acrolein. In order to understand the distribution characteristics of these carbonyl compounds, measurements were undertaken for three months (April to June 2007) to cover a total of 60 newly built apartments (i.e. ones built less than three months). The concentrations of formaldehyde, acetaldehyde, and acrolein measured during the entire study period averaged as 231 ± 164, 60.3 ± 28.9, and 7.8 ± 10.9 ㎍ m3, respectively (N = 60). Evaluation of threshold limit values (TLVs : TLV of a chemical substance defines the reasonable level to which a worker can be exposed without adverse health effects. Strictly speaking, TLV is a reserved term of the American Conference of Governmental Industrial Hygienists (ACGIH)) indicates that formaldehyde and acetaldehyde data exceeded the allowable values by 43 and 58 percent, respectively. In the case of total carbonyl compounds, 95 percent of the data exceeded the allowable TLV values.