The concentrations of six carbonyl compounds in indoor air were measured for selected public places in Hangzhou, including shopping centers, supermarkets, furniture store, inter-city bus stations, railway stations and cinemas. In indoor air of the public places, the mean concentration was 146.5 microg/m(3) for total carbonyls, in which formaldehyde was found to be the most abundant carbonyls with an average value of 90.6 microg/m(3) and followed by acetone and acetaldehyde. Among the selected public places, the furniture store presented the highest carbonyl concentrations in the indoor air, followed by shopping centers, supermarkets, cinemas, while the railway stations and inter-city bus stations presented relatively lower carbonyl concentrations. Carbonyl concentrations in indoor air for the different areas of shopping centers and supermarkets were also investigated. The results showed that the highest carbonyl concentrations were found in restaurant and bedclothes areas for shopping centers and in the cooked food areas for supermarkets. The average ratios of the indoor/outdoor (I/O) for carbonyl concentrations were greater than 1, which indicated that the indoor sources significantly contributed to carbonyls, such as indoor materials and anthropogenic activities. Preliminary estimate of the health risk for staffs, customers and passengers in public places was discussed.