Reactions of tetraethyldilithiostannole 1 with [Cp*RuCl](4) afforded not eta(5)-stannole dianion complexes but two novel bis(stannylene)-bridged dinuclear ruthenium complexes, which have butterfly and inverse-sandwich structures, respectively, depending on the stoichiometry of [Cp*RuCl](4) toward dilithiostannole. The redox behavior between the two complexes is found to be reversible. The molecular structures were determined by X-ray diffraction analysis. The Ru-Ru bond of the butterfly complex is 2.3428(6) angstrom, which is the shortest among those of dinuclear ruthenium complexes having Cp or Cp*Ru units. Theoretical calculations revealed that the very short Ru-Ru bond is due to the presence of one sigma bond between the ruthenium atoms and two three-centered bonds delocalized over the two Ru2Sn rings.