A survey is made of the quality of purified water used in the in the Acid Rain Monitoring Network of China Meteorological Administration (CMA) based on the station reports from 2006 to 2008. Statistics show that the quality of purified water has been improved gradually since the enforcement of the Standard Operation Manual (SOP) for Acid Rain Monitoring issued by CMA in 2005. Averagely, for the three years, the quality of purified water for 95% of stations meets the threshold requirement (conductivity less than 10 μS·cm-1) of SOP, and that for 83% of stations reaches the target requirement (conductivity less than 5 μS·cm-1). The sources of purified water can be roughly classified into four categories, i.e., selfmade distillated water at station, commercialavailable purified drinking water, distillated water from hospitals, and purified/distillated water from different factories/agencies. The percentage of commercialavailable purified drinking water in the total tends to increase in the last three years, and that of distillated water from hospitals decreasing accordingly. Among the four categories of purified water sources, the quality of the commercial available purified drinking water and that of the distillated water from hospitals are relatively good, and that of the selfmade distillated water is relatively poor as expected.