Radon is a radioactive gas, occurring naturally as a decay product of uranium .Radon is the second cause of lung cancer according to EPA and WHO estimates. The presence of cracks plays a major role in transmission of radon from depth to the surface of the earth and steams it into the air.The leakage of radon from the foundation soils is usually the primary source of indoor radon pollution. Due to the growth of urban population in active tectonic regions and because tectonic activity is accompanied by an increase in radon concentration; the emission of radon in these regions and its leakage into houses will be higher thus,it becomes necessary to conduct researches in those regions and take appropriate preventive and corrective actions to reduce the presence of radon in the houses and in foundation soils. The importance of this research comes from benefiting from measurements of the change of radon concentration and its implications from both Geotechnical and Geo-environmental aspects.