Submonolayers of Au on Si(111) exhibit various surface superstructures, 5×2, α-√3×√3, 2√21×2√21, 6×6, and β-√3×√3, depending on the Au coverage and heat treatments. We have succeeded in detecting the clear difference in temperature dependence of electrical conductivity among these Au/Si(111) surface superstructures by using the micro-four-point probe method. The conductivity of 6×6 is higher than that of the β-√3×√3 in the whole temperature range (130-300 K), though both surfaces have the same Au coverage, but are different in long-range order of atomic arrangement. The surface conductivity of both surfaces exhibit semiconducting temperature dependence of conductivity, while that of the α-√3×√3 show a metallic character, which is consistent with surface-state bands revealed by previous photoemission spectroscopy. [DOI: 10.1380/ejssnt.2005.497]