This study were conducted to estimate property of nitrogen dioxide concentration at industrial areas in Korea. The nitrogen dioxide concentrations were measured for 50 dwellings at Ulsan and Yeochon, respectively using the nitrogen dioxide filter badge forming the passive sampler from summer time 1998 to winter time 1999. The major results obtained from this study were as follows: 1. The mean indoor, outdoor, and personal concentrations of nitrogen dioxide during summer time 1998 in Ulsan were 28.9 ppb, 24.8 ppb, 24.8 pub, respectively. 2. The mean indoor, outdoor, and personal concentrations of nitrogen dioxide during winter time 1999 in Yeochon were 11.4 ppb, 12.5 ppb, 15.5 ppb, respectively. 3. The mean concentration of nitrogen dioxide during winter time 1998 were higher than the corresponding levels during summer time 1997 in Ulsan. 4. The mean concentration of nitrogen dioxide in Ulsan were in general higher than the corresponding levels in Yeochon. 5. This results in slightly positive correlation among indoor, outdoor, and personal nitrogen dioxide concentrations for summer time in Ulsan, then it statistical significance is showed(p <.05). These results suggest that nitrogen dioxide concentrations in industrial areas seem to be affected by traffic density and conditions of industrialization.