Abstract:Based on the hourly PM2.5 concentration data of 10 environmental monitoring stations of Guiyang in 2013 and 2014, the pollution characteristics of PM2.5in 2013 and 2014 are described. In combination with the comparative analysis of Guiyang hourly precipitation data, the change features of precipitation and particulate pollution are discussed. The results show: The annual mean value of PM2.5 was about 33 to 55 μg/m3; the monthly pollution concentration values were high in autumn, winter, and early spring, but low in summer. The daily variation of PM2.5 concentrations showed the typical structure with double peaks, and the value was high in morning and evening. When there is rainfall, average concentration is nearly 20% lower than that without precipitation annually. The PM2.5concentrations in rainy days were lower obviously than those without rain. In the rainy days, the concentrations of PM2.5 were reduced obviously especially during night and morning session, which was associated with the precipitation characteristics of Guiyang. Compared with the precipitation less than 1 mm, the removal and inhibition effect of precipitation greater than 1 mm was more remarkable.