Abstract: Using microwave radiometer data, which has a high temporal resolution, to analyze the relationship between the structure of the inversion layer and haze in Nanjing. First, in order to confirm the availability of microwave radiometer data, we compare the temperature and relative humidity data of the MP-3000A ground-based microwave radiometer in December 2013 with that of sounding data. The results show the temperature based on the microwave radiometer to be very close to that of the sounding, but their relative humidity values to differ greatly. Analyzing the haze in December 2013 with the data of the microwave radiometer, it is found that, due to the impact of straw burning (1-9 December), there is no significant correlation between pollutants and the inversion layer. However, in periods of no straw burning (10-31 December), there is a significant positive lag correlation between pollutant variation and the thickness and strength of the inversion layer, and a negative lag correlation between pollutants and the height of the bottom of the inversion layer. Through quantitative analysis, we reveal that the thresholds of inversion layers corresponding to heavy pollution are the same as with moderate pollution, while the thresholds of inversion layers corresponding to light pollution are weaker.