The relationship between the radioactive inert gas radon and lung cancer bas aroused much attention among people all over the world; as a result, re.earch work on radon in environment has been carried out in many countries. The distribution of parent elements of radon-uranium and radium-in geological environment has an intimate bearing on radon concentration in air. Therefore. a rapid and qualitative evaluation of radon concentration in air might be made through the study of uranium and radium distribution in geological environment.