In order to detect the change characteristics of road noise in horizontal direction and vertical direction. Road noise monitoring in Second Circular road and south of Chang′an road in the South Suburb of Xi′an. The average road noise of daytime in Second Circular road and south of Chang′an road is 7048 dB and 6891 dB respectively. The average values of road noise is 6603 dB and 6693 dB, over-standard 10 dB in the night. And increase of distance with the decreases value of road noise in horizontal direction. The value of road noise has significantly increased, then it is relatively stable, at the last the value of road noise is decreased in the vertical height of 70 m. Through analysis of transmission route and cause of road noise, put forward some countermeasures against road noise pollution： pavement widening, designing green belt along main roadsides, compounding plant community such as tree, shrub and herb reduce the effect of road noise, amelioration of road surface, adjusting traffic signal , strengthening traffic management and so on.

road noise; pollution monitor; controlling measures; south suburb of Xi′an