Vibrational excitation of single molecules at surfaces will open an ultimate way of the reaction control in nano‐meter scale. Direct excitation along the reaction coordinate coupled with the multiple excitations will lead to molecule‐to‐molecule chemistry. For the indirect process, anharmonic coupling between the excited vibrational state and the reaction coordinate plays an important role. Action spectrum for cic‐2‐butene on Pd(110) exhibits low frequency vibrational modes are excited by inelastic tunneling but are not clearly visible in STM‐IETS. © 2003 American Institute of Physics