Abstract: Radon is a gaseous substance of radioactive.It exists widely in groundwater and atmosphere:or in pores of soil and rock.In recent years,because of we have realized that generating inter radiation is factor of bring about lung cancer when radon was breathed in the body,thus draw internal and external attention.In the article, we have introduced conditions of radon concentration in some coal seames,and have analysed main factor which affect radon concentration in coal mines,presented practicable monitoring method and evaluating opinion.In order to provide reference materials for the monitor and assessment of the radon and exploration of coalfield.