GIS technique is applied to the analysis of ambient air quality information. For this study, the TMS-monitored air quality information was imported with the geographical information of the TMS stations in Capital Area. It is found that currently available GIS technique has a great extend of potential for air quality management. From the analysis of air quality information, the GIS application demonstrates the poor air quality in the central Capital Area and the it is improved as it travels down to the suburb area. The ambient air quality is also proven to be highly influenced by the ozone concentration in a mid-summer day.