Abstract: Under vibration with frequency 200Hz and amplitude 0.5mm, the changes of radon concentrd tion in soil gases have been observed. Their characteristics are as following:radon concentration increases during the vibration, after vibration it decreases to a level lower than that before vibration, and then it slightly returns. Three vibrational tests for the same sample showed that radon concentration turns to decrease mainly during the vibration with the increase of vibration times. Finally, the mechanism of change of radon concentration in soil gases under low frequency vibration is discussed.