| Beijing is the political, economical and cultural center of China with a huge population. As the rapid development of society and economy, a great many problems of environment come about. Organochlorine pesticide is a kind of persistent organic pollutants, and nowadays more attention is paying to its pollution and its harm to the human health. Because the quality of soil is closely related to the human health, it is very important and meaningful to do research on the residues of Organochlorine pesticide in agricultural soil in the suburb of Beijing.In this work, the characteristic distribution of the DDTs and HCHs residues in the agricultural soil were analyzed in both surface and deep soil samples. The risks of DDTs and HCHs residues were also discussed, and it could provide the reference for evaluation of entironmental geochemistry.The surface soil samples were analyzed and different concentrations of DDTs and HCHs residues were detected in the samples. DDTs residues were at a low level and∑DDTs ranged from 0 to 292.40μg/kg while p,p'-DDE and p,p'-DDT were the main residues of DDTs. The contents of∑HCHs in the samples varied from 3.33 to 53.92μg/kg. The distribution of different isomers was not uniform and it revealed the rates of isomers degradation were also different.Few DDT isomers were detected in the deep soil samples. The contents of DDTs were decreased with the increased depth. In one sample the four isomers of DDT were found in the first layer, and in the other only p,p'-DDE was detected. The HCHs were found in all the layers at different levels. The contents of HCHs weren't increased as the depth of soil profile increased obviously.The concentrations of DDTs in most soil samples were accorded with the first level of the national standard quality of soil environment (GB 15618-95). And the contents of HCHs were also lower than the standard. According to the results, we concluded that there was no new input of pollution in this area.
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