Abstract: According to radon environmental study on indoor and outdoor radon of uranium deposits in South China, it is shown that the air in the range of 0.5～1.5 km around the ore areas were seriously contaminated by the radon and its daughters releasing from the process of uranium exploration and mining, but the contamination level of radon rapidly decreased with the increase of the distance from the center of deposit area. The indoor radon concentration of inhabitant around the two study areas is high, about 10 times of average value of Guangdong. In all the 290 research dwellings, 45 (23%) have indoor radon level above 150 Bq/m³, a limit value of indoor radon concentration suggested by U.S. Environmental Protection Agency. The main reason of high level indoor radon concentration is that the study areas belong to high background radiation area, the soil and rocks in house basement have high content of U, Ra and Rn, and an amount of radon releasing from the soil and rocks entry the dwellings.