Abstract: The contents of Pb, Zn, Cd and As in the water of the Bijiang River and the speciation fractions of heavy metals in bed mud were determined and the distribution of heavy metals and speciation changes were analyzed. Results show that the water has been contaminated by Cd, while heavy metals have been highly enriched in bed mud. According to grade III of the national environmental quality standards for soils, the contents of Pb, Zn, Cd and As are separately 3.4, 15.8, 106 and 2.6 times higher than the standards. The distributions of contaminants show that the peak of heavy metal contents in water lies in the lower reaches near the mine, while the peak of heavy metal contents in bed mud is located 30-50 km downstream of the mine. The mining activities, terrain, warming of water flow, pH and other water body environmental changes all can affect the contents of heavy metals in water and bed mud. In the bed mud, Pb mainly occurs as the carbonate binding state and Zn and Cd as the Fe-Mn oxide binding state, while As mainly occurs as the residual state. The contents of environmental available states of Pb, Cd and Zn are relatively high in the Lanping area, which has great potential danger to the eco-environment of the Bijiang River drainage area.