Some organic molecules were designed and based on the combination of thiophenyl and phenyl structural moiety. These thiol compounds form the Self-Assembled Monolayer(SAMs) by a spontaneously chemical reaction on the surface of gold. The conductance of these SAMs were measured by conductive Atomic Force Microscopy(c-AFM)technology. The experimental results showed that the conductivity were determined by the length of methylene group of the anchoring site.