Thirteen carbonyl compounds in indoor and outdoor air at three general residential homes in Xi’an during winter and summer were detected and quantified by using active gaseous sampling with 2,4-DNPH absorption and the following HPLC analyses. The results indicated that the concentrations of carbonyl compounds were relative high indoors both in winter and summer. Averaged concentrations of carbonyl compounds were 85.86±30.33 µg•m-3, and 78.86±31.40 µg•m-3, respectively, for indoors and outdoors in summer. The corresponding values were 85.40±28.50 µg•m-3, 53.77±16.39 µg•m-3, respectively, in winter. Concentration levels of carbonyl compounds indoors were higher than those outdoors. Formaldehyde, acetaldehyde, and acetone were the highest components, accounted for 75%~80% of total mass of carbonyl species. Concentrations of carbonyl compounds in H2 (the second residential home) were larger than those in other two houses, which implied that decorated materials and smoking contributed significantly to the high concentrations of carbonyl species in H2.