A pilot study was conducted in order to investigate the concentration of formaldehyde at elementary school, middle school, the high school (108 classrooms) located in Chungchong-namdo during February - September, 2006. Also, divide by (45 classroom) General Classroom and (63 classrooms) Stateroom. The average concentrations of formaldehyde(HCHO) in the general classroom was high by $22.87;{pm};20.61;{mu}g/m^3$ elementary school, $22.08;{pm};12.70;{mu}g/m^3$ high school, $13.58;{pm};6.60;{mu}g/m^3$ middle school. The average concentrations of formaldehyde(HCHO) in the Stateroom was high by $27.58;{pm};30.5{mu}g/m^3$ elementary school, $22.03;{pm};19.12;{mu}g/m^3;22.87;{pm};20.61;{mu}g/m^3$ middle school, $24.92;{pm};28.15;{mu}g/m^3$ high school. There was correlation between formaldehyde concentrations and temperature, humidity in general classroom (P<0.05).