We had established an acidic deposition network including 70 sites in Guangdong and Guangxi provinces and had done routine monitoring work on dry deposition and wet deposition simultaneously from January, 1988 to December, 1989. The results showed that frequency of acid rain was rising and was distributed along main wind direction from north to south in Guangdong and Guangxi provinces. The acidity of rain water was the most acidic and acid rain occured most frequently during spring season. The chemical composition of rain water were mainly Ca2+ , NH4+,SO42-. The average ratio of SO42-/NO3 -was 2. 7 times larger than that of the United States. The chemical components in rain water were mainly sulphate and it indicated that the acid rain in Guangdong and Guangxi provinces was caused by air pollution from coal burning.