To investigate the contamination levels of heavy metals, surface water and sediment samples were collected from 21 sites along the Gan River. The heavy metal concentrations (V, Co, Cr, Ni, Cu, Zn, Cd, and Pb) were determined using inductively coupled plasma spectrometry (ICP-MS). The results demonstrated that the status of the surface water and sediments as a whole were relatively clean with regard to heavy metals (except for Cd) compared to water quality standards and sediment quality guidelines. The two heavy metal sources of the surface water and sediments were identified separately using factor analysis (FA). High levels of metals were found in the sediment in the upstream and downstream due to frequent mining and industrial activities, whereas concentrations of heavy metal in the surface water from two sources were abundant in the upstream and midstream – likely related to mining activities and sediment suspension. As indicated by enrichment factor (EF) and potential ecological risk index (PERI), Zn, Pb, and Cd were the most anthropogenically enriched metals, while sediments in the upstream and downstream had high potential ecological risk. Local people, including adults and children who ingested water from the Gan River, showed little potential non-carcinogenic risk, as the hazard index (HI) scores were less than 1. Compared with those in other rivers in the world, heavy metal enrichments in surface water and sediments were of moderate levels.