摘要
In this work, concentrations of radon indoor were measured at 10 locations in Al-Kufa and Al-Najaf cities, using RAD-7 radon monitoring system of Durridge Company USA. Some factors affecting on the radon factor have been studied such as times of day （morning, aitemoon and evening） and seasons of year （winter, spring, summer and autumn）. This study show that the radon concentration indoor increases at mornings, evenings, decreases at afternoon, also increases in winter and autumn, decreases in spring and summer.
