Abstract:Arsenic is widely distributed in the environment. As teratogen, carcinogen or mutagen, it has extremely toxic effect on mammalian health. Recently, as the outbreaks of arsenicosis in many countries such as Bangladesh and China, arsenic toxicity or pollution has been a global problem, severely threatening tens of millions of people’s health. Therefore, studies on the transfer of arsenic toxicity or pollution are important. The threat of pollution and toxicity from the dispersal of naturally occurring and anthropogenic arsenic stimulated extensive studies focusing on the geochemical behaviors, such as mobilization and transformation of arsenic. More evidences suggest that microbes play an important role in the geo-chemical circulation of arsenic. Some microorganisms have evolved to tolerate relatively high concentrations of arsenic by methylation and/or redox. These microbial processes, together with inorganic and physical processes, constitute the global cycle of arsenic. In this article, we review the diversity of microorganisms known to interact with arsenic, and the genes and enzymes involved in these processes. We also briefly discuss the application of arsenic bio-transformation is . Finally, according to the studies in our laboratory, we propose the potential application in medical sciences and its future pros-pects.