The characteristics of spatial and temporal distribution of tropospheric NO₂ column density over Yangtze River Delta for 2005~2014 were analysed based on satellite derived NO₂ column data from OMI. On this basis, influencing factors of NO₂ changes were analysed from terrain, meteorology, economy, agriculture, life, national major environmental planning, and other aspects. Results demonstrate: a) Tropospheric NO₂ column density increased at the annual rate of 1.04%, with the highest column density 1184.07×10¹³ mole/cm² in 2011; it raised 20.7% compared with 2005 in 2010 and declined 9.1% compared with 2010 in 2014; b) The spatial distribution of tropospheric NO₂ column density had significant change, high in the middle, low in northern and lower in southern of Yangtze River Delta. c) Precipitation had a highly negative correlation with NO₂ concentrations for the reason of atmospheric wet deposition. The terrain of Yangtze River delta weakened the unfavorable impact of the high polluted area under the effect of the dominant north wind. d) Tropospheric NO₂ concentration had a correlation coefficient of 0.83 with the second industry output value, and a correlation coefficient of 0.74 with car ownership. Tropospheric NO₂ concentration was closely related to coal consumption and car ownership; in addition, the agricultural straw burning also released a large amount of nitrogen oxides. Series of NO_x emission control measures such as controlling amount of coal and denitration applied during the "twelfth five-year" lowered the NO₂ concentration in 2012~2014.