Over the past 50 years,large amounts of uranium waste rocks and tailings resulting from the exploitation and treatment of uranium ore have been accumulated in dams(tailing ponds)at the Northern Guangdong mine(South China).These radioactive solid wastes exposed in the environment,long-term subjected to wind erosion and rain leaching.The water and soil in the surrounding environment would be polluted with higher 238U,226Ra and other heavy metals(Mn,Pb,Zn,Cr,Cu,Ni,et al.); it will threaten the safety of the local ecological environment.The vertical distribution concentrations of some natural radionuclides and heavy metals measured in soils and sediment profiles taken from the downstream of uranium smelting plant(USP)was studied.The soil samples were collected from the surrounding of USP and the sediment from the main mountain streams.The concentrations of 238U and 226Ra in the sediments around the outflow and in reservoir are higher than the middle reach; the contents of 238U attain to 1500 mg? kg–1 in reservoir deposit and more than to 3200 mg?kg–1 in pond deposit,it will influence the water quality for a longtime.One of the possible explanations for this phenomenon can be the different chemical dynamics of 238U in the main mountain stream sediment.The contents of heavy metals for Pb,Zn,Cr and Cu in pond sediment are 13.5,3.8,6.8 and 8.5 times respectively higher than the large reservoir sediment in northern Guangdong province.While the content of U,Mn and the specific activity of radionuclids 238U and 226Ra are 588,141,510 and 983 times respectively higher than soil background values in Guangdong province.There has strong correlation between some radionuclids and heavy metals at the polluted vertical sediment profiles.This result indicates that the pond is greatly influenced by uranium smelting plant,and there is already a high level of environmental contamination for 238U,226Ra and some heavy metals.In addition,the pollutants of the pond profiles had a surface-enrichment trend,indicated that there may be an aggravated-pollution tendency in recent years.The study has a relatively positive significance to investigate the content of radionuclids and heavy metals of stream sediments and soils surrounding the uranium workspace,to make sure the pollution episodes of different regions,to establish uranium mine environmental pollution prevention and control measures.