The statistical characteristics of precipitation acidity and conductivity at Nangong are discussed by means of the acid rain monitoring data from 2006 to 2009. Results show that the average precipitation pH is 5.22, with the lowest being 3.08; the averaged precipitation conductivity is 94.1 μS/cm with the highest value being 529.0 μS/cm for the 4 years; the acid rain frequency (pH<5.6) is 63%, which accounts for 80% of total precipitation amount of the four years; the severe acid rain frequency (pH<4.5) is 28%. Nangong is an area suffered from acid rain pollution relatively heavy in North China. The acid rain frequency shows a seasonal variation, high in autumn and low in spring. Consequently, the precipitation pH is low in autumn and high in spring. The relationships of precipitation acidity variation with surface wind conditions, precipitation amount, and precipitation types (including fog) are also discussed.The acid rain frequency in the daytime (10:00 to 16:00) is only 31%, much lower than that in the nighttime (72%). The diurnal variation of local PM10 can be attributed to the differences of precipitation acidities in the daytime and nighttime.