Abstract: Based on the observational data of acid rain, the ground meteorological data in Nangong from 2006 to 2010, the sounding data and synoptic situation, the characteristics of acid rain and the effect of meteorological conditions on it were analyzed. The results indicate that the mean pH value of precipitation is less than 4.70 in Nangong and acid rain frequency is more than 50%, so it belongs to the serious or more serious acid rain area. The acidity of precipitation is stronger in summer and autumn, while the frequency of acid rain is high in autumn and winter. The conductivity of precipitation is the largest in winter. Acid rain often occurs when the dominant wind is the eastward, calm and north-northwest wind. The frequencies of acid rain and serious acid rain increase with the increase of precipitation grade when upper weather system is a shear line. The intensity of acid rain increases with the increase of relative humidity and inverse temperature.

Key words: Acid rain, pH value, K value, Frequency of acid rain, Influencing factors