The authors present the results of tunneling measurements done on window-type, native-barrier YBa2Cu3O7-δ-Pb junctions. They show features in the I-V curves which are related to the gap of YBa2Cu3O7-δ, as well as to the Pb and YBa2Cu3O7-δ phonon spectra. The nature of barrier in these structures is found to be semi-conducting. They can also see the asymmetry in the tunneling curves