Diurnal variations of air quality for each season over Taeau city were analyzed using the characteristic features of the various synoptic wind fields. The air quality data which were monitored by four stations are the hourly averaged sulfur dioxide($SO_2$), total suspended particulate(TSP) and oxidants ($O_3$) during the period of 1989 to 1992. The various synoptic wind fields obtained from the 850 hPa geopotential height were divided in to four geostrophic wind directions and two geostrophic wind speeds for each seasons. The synoptic weather conditions were again subdivided info two categories using the lotal cloud amounts, The results shows that diurnal and seasonal variations of the air quality over Taegu city, such as sulfur dioxide, total suspended particulate and oxidants reseal the various characteristics under the same synoptic weather conditions.