The conductivity and pH value are statistically analysed based on the 557 rainfall samples between 1992 and 1994 at 5 monitoring stations which focus on the observationary station directly belong to Chengdu Meteorological Bureau. And detail analysis under the meteorological conditions is abtained. Results show that annual average pH value in Chengdu is 5.57 and the frequancy of acidrain is 37.4%. The acidrain happens dominantly between July and September,and is related with meteorological conditions.