The article analyses the annual and monthly average value and hourly monitoring data of nitrogen dioxide in YuZhong District during twelfth Five-Year in order to find out the variation tendency of nitrogen dioxide in the period，the nitrogen dioxide concentration in YuZhong District was comparatively fairly high with yearly increase in the twelfth Five-Year，the nitrogen dioxide became the primary pollutants instead of particulate matter in YuZhong District in 2015，the research shows the most of nitrogen dioxide in the atmosphere of YuZhong District from automobile emission in downtown area and it shall draw attention of authorities concerned.