The electronic property of CoPc/Au(1 1 1) interface was investigated by angle-resolved ultra-violet photoelectron spectroscopy (ARUPS). Combining the ARUPS data with density functional theory (DFT) simulation, the correspondences between the emission peaks and the molecular levels were established. The interfacial charge transfer and the variation of the spin polarization of the adsorbed CoPc and the underneath gold atom indicated a strong interaction between the adsorbate and the substrate. Several conductance resonance peaks at specific molecular energy levels for CoPc molecule, and an adsorbate-substrate interaction brought modification to the quantum conductance spectrum for CoPc/Au(1 1 1) system were found by the first principle transport calculations. (C) 2014 Elsevier B.V. All rights reserved.