Concentrations,distribution and enrichment of heavy metals in the bottom mud of Lake Taihu are investigated.The method of potential ecological risk index presented by Lars HKanson is used to assess the ecological risk of heavy metal pollution.The results indicate that the distribution of various heavy metal contents appears a regional distributive character,i.e.the mean contents of heavy metals are relatively high in the field of lakeshore and low in the center.Among these heavy metals,the enrichment of Pb appears highest and the others appear lower.The order of the enrichment degree of heavy metals in the bottom mud of Lake Taihu is Pb>Zn>Cu >As >Cr >Hg >Cd.The assessment results of ecological risk reveal that except Hg pollution in Du Shan-kou belongs to moderate potential ecological risk,all the others belong to light potential ecological risk.The order of the polluting degree of heavy metals in the bottom mud of Lake Taihu is Hg>Cd>Pb>As>Cu>Zn>Cr.