Abstract: With investigation of automobile flow,NO_(x) concentration and the meteorological features of Luoyu Road in Wuhan City,the characteristics of traffic flow and NO_(x) distributing are analyzed,and are simulated by use of the street canyon diffusion mode.Based on that,the diffusion mode of city automobile emission is depicted integrating GIS,and by use of data-base or second empolder of GIS,the distributing laws of space time about pollutant arereflected straightly and dynamicly.