A systematic study of the electronic structures of natural galena containing ten typical kinds of impurities is performed by the density-functional theory (DFT). Mn, As, Bi. In and Sb impurities make the Fermi level shift to the higher energy level, while Ag, Cu and Tl impurities make the Fermi level shift to the lower energy level. Mn, In, Sb, Zn and Tl impurities result in a decrease in the Mulliken charge of the Pb atom and might decrease the ionicity of galena, whereas Ag. Cu, Bi, As and Cd impurities lead to an increase in that of the Pb atom. The frontier orbital calculations show that Sb and Mn impurities might lead to the over-oxidation of galena. and thus are unfavorable for the flotation of galena. (C) 2010 Elsevier B.V. All rights reserved.