Together with the concern about the indoor all quality as sick house syndrome, the Ministry of Environment announced "Indoor Air Quality Control Law for the Multi Purpose Facility," which made the interests to be focused in the urgent understanding of current condition and preparation of measures about the indoor air pollution. In Dec 2005, the law was revised to obligatorily notify the amount of Formaldehyde and Volatile Organic Compounds in the case of newly constructed apartments with more than 100 houses. School also have its own indoor air quality guideline, Indoor air quality in school is very important because, children who very weak to indoor pollutants reside long time in there. The purpose of this paper is to survey indoor air qualify in school by field measurement. Field measurements were performed in 11 schools which were selected from 3 major cities(Incheon, Dae-jeon, chuncheon) in korea, during July, 2004. Totally concentration of Indoor pollutants were determined in 27 classroom. Target air pollutants were TVOC, formaldehyde, dust, CO, CO2 and NO2. For the result of this investigation, Indoor air quality in classroom was very poor and it was found that some pollutants (TVOC, float bacteria) exceed the guideline.