The authors investigated fault gas levels in three sites, namely Yuhu site located in Rongjiang Fault, Guangtai site located in Bomei-Chaoan-Sanrao Fault and Raoping site located in Huanggangshui Fault. The authors got Radon concentrations and analyzed its distribution characteristics in these regions. The background level of Radon in Eastern Guangdong Province is during 50~88 Bq/L. The background level of mercury in Raoping site is approximately 35 ng/m3. According to these abnormal distribution of fault gas, it is estimated the fault location in Guangtai and Raoping site.