Sediments function as a sink for heavy metals from diverse sources,reflecting the natural soil composition of the surrounding areas,as well as human activities.A total of 8 surface sediment samples were collected to investigate heavy metals pollution characteristics and potential ecological risk assessment in surface sediments from Qingshan Reservoir in Linan City of Zhejiang Province,East of China.The total contents of As,Cr,Cu,Ni,Mn,Pb and Zn were analyzed and compared.The BCR sequential extraction method was used to determine the four chemical fractions of heavy metals such as acid soluble,easily reducible,easily oxidizable and residual fractions.The heavy metals pollution and potential ecological risk were evaluated systematically using geoaccumulation index(Igeo)and Hakanson potential ecological risk index(H).The results showed that there were significant differences in spatial distribution in the total concentrations of heavy metals in the surface sediments of Qingshan Reservoir.The sampling sites from the estuaries of tributary flowing through downtowns and heavy industrial parks showed significantly higher average concentrations of heavy metals in the surface sediments,as compared to the other sampling sites.Chemical fractionation showed that the heavy metal Mn existed mainly in acid extractable fraction,and Cu and Pb were mainly in reducible fraction,while arsenic(As)existed mainly in residual fraction in the surface sediments despite sampling sites.The sampling sites from the estuary of tributary flowing through downtown showed significantly higher proportions of acid extractable and reducible fractions in total heavy metals than the other sampling sites,which would pose a potential toxic risk to aquatic organisms as well as a potential threat to drinking water safety.As showed the highest pollution indices among the investigated 7 heavy metals,followed by Pb,Ni and Cu,respectively,which were at moderately-polluted level.Zn,Cr,and Mn were at relatively low potential ecological risk with low Igeo and H.The sampling sites from the estuaries of Jin River and Heng River,which flow through downtowns and heavy industrial parks,respectively,showed significantly higher heavy metal pollution levels and potential ecological risk in the surface sediments,as compared to the other sampling sites.Especially As,Pb and Ni are potentially harmful to aquatic environmental and ecological system of the Qingshan Reservoir based on the chemical fractionation and ecological risk assessment.Further monitoring and supervising schemes that focus on these three metals are necessary and exigent.