The temperature inversion in the boundary layer is an important indicator of atmospheric stability.The strong inversion may result in the accumulation of pollutants in the lower layer.In addition,the accumulation of strong inversion energy can also cause severe convective weather.All of these have a huge impact on the production of human life.In order to analyze the characteristics of temperature inversion in the boundary layer (below 2 km) over Nanjing City,this paper used the daily L-band radar data at 08:00 BST and 20:00 BST from 2010 to 2015.The frequency,intensity and thickness of ground temperature inversion and suspended inversion were analyzed in detail.The results reveal that the frequency of temperature inversion is high over Nanjing,up to 81.68%,including 23.9% ground inversion and 71.8% suspended inversion.The frequency of temperature inversion at 08:00 BST is higher than that at 20:00 BST.The temperature inversion occurs mostly in autumn and winter and rarely in summer.The inversion thickness is the lowest in summer and the maximum in winter and early spring.The inversion thickness at 08:00 BST is larger than that at 20:00 BST.The thickness of suspended inversion is larger than that of ground inversion.This phenomenon is due to the change of solar radiation.Solar radiation increases temperature at day time and strengthens the turbulence,resulting in the inversion weakened or disappeared.On the contrary,the ground temperature gradually decreased at night with the turbulence weakening,which resulting in the inversion intensity and thickness strengthened.The inversion intensity is weak in summer and strong in winter,which has an obvious seasonal variation.There is a little difference in inversion intensity between 08:00 BST and 20:00 BST.But the average of ground inversion intensity is 1.5 times of suspended inversion intensity.Most of strong inversion with intensity higher than 2℃/hm happened in winter.Based on the daily monitoring data of mass concentration of air pollutants in 2014 and 2015,the paper analyzed the relativity of pollutant mass concentration and inversion elements (inversion intensity and inversion thickness).The results reveal that the mass concentrations of pollutants (PM₁₀,PM_2.5,NO₂,SO₂ and CO) are in positive correlations with the inversion intensity and thickness.In other words,the stronger the inversion layer,the higher the pollutant mass concentration.The mass concentration of ozone is in a negative correlation with the inversion intensity and thickness,which is related to the diurnal variation of ozone mass concentration.Therefore,the atmosphere inversion in the low layer is one of important factors that influence the air quality.The changes of the inversion elements (inversion intensity and thickness) have certain directive significance to air quality forecast.