Abstract: ObjectiveTo determine concentrations of main indoor volatile organic compounds(VOCs)and nitrogen dioxide pollution level and their influencing factors.MethodsAccording to different time after room decoration,99 households were randomly selected in a residential district of Dalian.Air was sampled in bedroom,kitchen and outdoor and a questionnaire survey was conducted among the residents of the district.Nitrogen dioxide and VOCs in the air samples were determined.ResultsIn the bedrooms,the concentrations of formaldehyde,benzene,toluene,and xylene were 37.3,6.8, 15.5,and 9.0μg/m³ and those of in the kitchen were 39.8,12.7,18.8,and 9.8μg/m³,respectively.The indoor concentrations of VOCs were higher than those of outdoor(P<0.05).Within one year after decoration,the concentration of benzene, toluene,and xylene in bedroom and kitchen were significantly higher than those more than one year after decoration(P<0.05).The concentration of formaldehyde and nitrogen dioxide in the rooms which green plants were placed were low er than those of without green plants(P<0.05).ConclusionIn winter,VOCs are the main indoor pollutants in decorated rooms.The concertration of the main VOCs decreases with the time after decoration,especially benzene,toluene,and xylene which decrease rapidly.Indoor plants can absorb and eliminate indoor air pollution to some extent.