Abstract:With the data set obtained at 31 meteorological stations in 2005, spat ial distribution and seasonality of precipitation acidity over Chongqing area we re analyzed. Meanwhile, based on the statistics of long term data set of 5 acid rain monitoring stations among the above meteorologi cal stations (Shapingba, Fuling, Wanxian, Fengjie and Badong), the spatio-tempor al distribution and seasonal ity of acid rain in recent 10 years (from 1997 to 2006) were discussed. The resu lts indicate a large discrepancy of acidity and conductivity of precipitation ov er Chongqing area. The seasonality of precipitation acidity is obvious in Chongq ing area as a whole. pH value of precipitation in spring and summer higher than in autumn and winter. The acidity of precipitation in the southwest part of Chon gqing is stronger than other parts, and the conductivity also higher. However, t here was no significant trend in the acidity and conductivity of precipitation d uring last 10 years in the southwest part. The precipitation acidity aggravated and conductivity increased significantly in northeast part of Chongqing in recen t 10 years, although pH value and conductivity data sets showed the precipitatio n in this part less polluted. The seasonality of acidity and conductivity of pre cipitation in the northeast part of Chongqing is more pronounced. The trend of t he precipitation acidity in the northeast part of Chongqing is mainly caused by the decrease of pH value in summer and autumn. The pH value and conductivity of precipitation at Fuling are much higher than the surrounding areas, suggesting t he importance of local influences.