|The concentration of air pollution in a large city such as Pusan has been increased every years due to the increase on fuel consumption at factories and by vehicles as well as the gravitation of the population. In this study, we have analyzed NO_2 concentration data and various data of meteorological factors during 1994-1997 to investigate the characteristics of NO_2 concentration and how the high NO_2 concentration is generated under the meteorological condition. According to the study, NO_2 peak concentration at most sites occurred about 1h later after the rush hour. In the characteristics of emissions in sites, sinpyeong- dong was highly contributed to point source while the other sites were highly contributed to line source. The high NO_2 concentration had high generation probability when temperature contained typical seasonal characteristics and wind speed was low. Using the relationship between meteorological factors and the daily average NO_2 concentration, correlation analysis was practiced. The seasonal variation of the daily average NO_2 concentration was correlated with air temperature, solar radiation and wind speed, but the correlation coefficient between meteorological factors and the daily average NO_2 concentration was not so much high. Thus we have known that the daily average NO_2 concentration is partially explained by meteorological factors.