We have performed a molecular dynamics simulation to investigate the ionic conductivities of the 1-n-butyl-3-methylimidazolium salts [BMIM](+)[Anion](-) as ionic liquids, where the anions are PF6- and the fluorinated organic anions CF3COO-, C3F7COO-, CF3SO3-, and C4F9SO3-. We developed bonded force field parameters for the anions and applied them to the molecular dynamics simulations. The calculated ionic conductivities are qualitatively in good agreement with the experimental values, demonstrating that the volume and self-diffusion coefficient of ionic liquids are important factors in determining the ionic conductivity of ionic liquids. (c) 2005 Elsevier B.V. All rights reserved.