Abstract: This research examined the metal contents in sediments and their potential eco-environmental impacts following the Beishan Pb-Zn mine's tailing dam collapse due to a catastrophic flood in 2001 on the Dahuanjiang River. The accumulation characteristics of As, Pb, Cd, Cu and Zn in 77 samples from 21 sites along the Dahuanjiang River from the north to the south were analyzed, and the current pollution status and environmental risks of five heavy metals were assessed by using sediment quality guidelines, pollution load index and potential ecological risk index. The results show that the mean pH value of sediment profiles were in the range of 2.09-7.51, and 38.1% of the samples had pH values lower than the upper limit of the Huanjiang background soil. The mean concentrations of As, Pb, Cd, Cu and Zn in the sediment surfaces (0-25 cm) were 3.2,0.0,9.2,2.1 and 17.0 times higher than those of the Huanjiang valley, respectively. There were two main types of heavy metal distribution in the sediment profile. From top to bottom, one decreased first then increased or remained unchanged, while the other increased first then decreased or remained unchanged. In addition, significant correlations were found between As and Pb, As and Cu, Cd and Zn, Pb and Cu, and Pb and Zn. According to SQG, the contents of Pb, As, Cd, Zn and Cu in the sediment first layer (0-22 cm) have substantial negative effects on water organisms. Pollution load index of 2.57 indicated very strong heavy metal pollution in the Dahuanjiang River basin. Compared with the Huanjiang background soil, the sediments surface (0-25 cm) of the Dahuanjiang River showed a strong to very strong ecological risk, with the pollution levels of the five heavy metals in the order of Cd>Pb>As>Zn>Cu. The heavy metal contents in sediment of Dahuanjiang River increased sharply and were difficult to recover since the tailing dam break.