Energy transfer effect between molecules adsorbed on rough silver surface has been studied by means of fluorescence spectroscopy. Enanced acceptor fluorescence and quenched donor fluorescence have been observed experimentally. On the basis of surface local electromagnetic theory, it is found that the non- radiative energy transfer rate between molecules adsorbed on silver surface is enhanced by two orders of magnitude when the molecular frequencies lie on the vicinity of resonance frequency of surface plasma. The results provide evidence for surface-enhanced energy transfer effect between molecules.