The acid rain observation in Nanning is analyzed.The results show that the acid rain frequence and the acidity in Nanning are both high, the frequency of acid rain in 2000 is 61.8%.The frequence is lower in summer half year and higher in winter half year. The relationship between acid rain and weather in different seasons is also analyzed. The seasonal distribution characters of acid rain have obviously relativity with the upper and surface wind direction freguency and the atmospheric circulation.