Abstract: Contents of formaldehyde and benzene in indoor air (released from fitment materials and furniture) were determined by national standard methods. Statistics of the analytical data from more than 1000 samples collected from Beijing area in one year indicated that formaldehyde and benzene contents in most samples exceeded the critical values. The maximum values appeared usually in June, July and August and the contents of formaldehyde of indoor air increased with room temperature, humidity, but had little correlation with atmospheric pressure. Humidity greatly affected the release of formaldehyde. The release of benzene had no obvious correlation with temperature， humidity and atmospheric pressure.