Abstract: Distribution,potential sources and risks of organochlorine pesticides(DDT and HCH) in the soils of the Xixi National Wetland Park were researched.Results show that HCH and DDT could be detected in all the topsoil samples.The ∑HCHs and ∑DDTs residues were similar with mean content being 18.44 ng·g^-1 and 20.80 ng·g^-1,respectively.HCH residues in the soils of persimmon orchards, bamboo gardens,bulrush bottomlands,vegetable farms and others were similar,while DDT residues in the soils of vegetable farm were higher than in the others. ∑HCHs and ∑DDTs in the soils were lower than the most stringent criteria(the first grade criterion,50 ng·g^-1) of the Soil Environmental Quality Standard of China(GB 15618-1995).In comparison with other places of the country,Xixi is relatively lower in ∑DDTs,but higher in ∑HCHs.The eco-risk analysis shows that HCH residues in the soils do not pose much risk to the geobiont therein,while DDTs do have some risk to the birds and geobiont.

Key words: soil, Xixi wetland, HCH, DDT, spatial distribution, risk assessment