Abstract: A study on the anthropogenic 129I in the environments around the high radioactivity sites has been carried out. The samples were collected from the surface waters and ground waters. 129I contents in the samples were measured using the AMS system at the China Institute of Atomic Energy. The 129I contents in The measured samples around the high radioactivity sites range from 108 atoms/l to 109 atoms/l. The result shows that 129I contents in the water samples collected in the vicinity of high radio-activity sites is many orders of magnitude higher than the content in the original rain water. 129I may be used as an environment monitor around the nuclear sites.