The noble metal (Ru, Rh, Pd, Pt)/Co3O4 system was studied by electrical conductivity measurements combined with temperature-programmed reduction (TPR). The results indicate that noble metals decrease the activation energy of Co3O4 and improve the reduction of Co3O4 due to hydrogen spillover. The promotional effect of Pt on the reduction of Co3O4 is most significant among the examined noble metals. By the electrical conductivity study of the unpromoted and the Pt promoted Co3O4 samples in oxygen and syngas, it can be drawn that the addition of the noble metal Pt can facilitate the oxidation of Co and the re-reduction of the cobalt oxides.