This study was carried out to evaluate the temporal (daily, weekly, and seasonal) variations of volatile organic-side site in a heavy-traffic central area of Metropolitan Taegu.Ambient air sampling was undertaken continuously for 14 consecutive days in each of four seasons from the springof 1999 to the winter of 2000. The VOC samples were collected using adsorbent tubes, and were determined bythermal desorption coupled with GC/MS analysis. A total of 10 aromatic VOCs of environmental concern were± p-xylenes, styrene, o-xylene, 1,3,5-trimethylbenzene,1,2,4-trimethylbenzene, and naphthalene. Among 10 target VOCs, the most abundant compounds appeared to betoluene (1.5~ 102 ppb) and xylenes (0.1~ 114 ppb), while benzene levels were in the range of 0.3~ found that the general trends of VOC levels were significantly dependent on traffic conditions at the sampling sitesince VOC concentrations were at their maximum during rush hours (AM 7~ 9 and PM 7~ 9). However, someVOCs such as toluene, xylenes, and ethylbenzene were likely to be affected by a number of unknown sources othersampling site. In some instances, extremely high concentrations were found for these compounds, which can not beexplained solely by the impact of vehicle exhaust. The results of this study may be useful for estimating the relativeimportance of different emission sources in large urban areas. Finally, it was suggested that the median value mightbe more desirable than the arithmetic mean as a representative value for the VOC data group, since the cumulativeprobability distribution(n=658) does not follow the normal distribution pattern.