This study was performed to investigate the characteristics of indoor air quality (IAQ) in elementary and middle schools in Gyeongbuk area from July to November 2006 . The measurements of indoor air pollutants were made to cover such components as PM-10, CO2, CO, NO2, O3, HCHO, TVOC, TBC, and Radon from school classrooms. The results of this study can be summarized as follows: all of them were less than IAQ standards of Korea. The mean concentration were measured by 43.0 ㎍/㎥ (PM-10), 745 ppm (CO2), 56.1 ㎍/㎥ (HCHO), 350 CFU/㎥ (TBC), 0.026 ppm (O3), 0.6 ppm (CO), and 59.2 ㎍/㎥ (TVOC). Radon was not detected in all surveyed classrooms. The I/O ratio of PM-10 was 0.8～1.4, while that for HCHO was 5.7～9.0. Therefore, it was concluded that the indoor pollution of formaldehyde was very serious in classroom. Keywords：New school, Indoor air quality (IAQ), Indoor air pollution (IAP), I/O ratio.