[Objective] We aim to investigate the effects of heavy metals in surface sediments of catchment rivers in drinking water source areas (Dongpu reservoir and Dafangying reservoir) in Hefei City of Anhui Province on downstream reservoirs. [Methods] Twenty-three sediment samples were collected from three major river catchment to determine the concentrations of Zn, Cu, Cr, As, Cd, Pb and Hg. The potential ecological risk was assessed by the potential ecological risk index (I_R) and cumulative index method (I_geo). The principal component analysis was used to assess the possible sources of the heavy metals. [Results] The distribution of heavy metal in the study area was different. The contents of As and Cd in sampling locations of C₁ and C₂ on the Surabaya river exceeded the secondary standard limit of soil environmental quality for maintaining human health, and the available Cd in these two sites accounted for 34.97% and 37.67% of total Cd concentration, showing a strong biological availability. Cd ecological risk index was generally high, reaching the intensity level, among which C₁ and C₂ on the surabaya river reached the extremely strong level. In addition, the ecological risk of Hg for location S₈ reached the intensity level, and the ecological risk level of the remaining 6 heavy metals was relatively low. The heavy metals in this region mainly came from human-natural mixed sources and human-made sources, with contribution rates of 51.11% and 27.70%, respectively. [Conclusion] Cd pollution is more serious in the lower reaches of the Sishui River. In order to reduce its impact on the downstream reservoir, Cd pollution control should be strengthened.