Abstract: The volatile organic compounds of air in the department room and the office after decoration were sampled and analyzed,while the outdoor air was investigated.Over 20 kinds of VOCs were detected in indoor air.The concentration of indoor air is higher than that of outdoor air.In one year after decoration,formaldehyde concentration of indoor air is 0 1～2 4 mg/m³,and in a short time after decoration it is higher,sometimes up to 13.4 mg/m³;benzene concentration of indoor air is 0.03～0.17 mg/m³.In one year after decoration,formaldehyde,benzene and styrene generally overpass the national standards.Halogenated hydrocarbon concentration of indoor air is 1～10 μg/m³,without significant difference from that of outdoor air.