Abstract: Objective To explore tolerance of several selected microorganisms to arsenic.Methods The selected mi croorganisms were cultivated at 37℃ in culture media with different concentration of sodium arsenite and counted by microscope,and arsenic content in bacteria was detected by ASA.Results Colifrom bacterium,staphylococcus albus,cerea bacillus,bacillus aeruginosus and yeast fung us can resist to arsenite.Conclusion The selected microor ganisms in the study have the a bility to tolerate arsenic and coliform bacterium have the ability to accumulate arsenic.