Bulk electronic structures of Pr-based filled skutterudites and their reference materials have been investigated by bulk-sensitive photoemission spectroscopy using soft and hard X-rays. For Pr 3d-4f resonance, a strong intensity in the vicinity of Fermi level (EF) is observed only for PrFe4P12. Furthermore, PrFC4P12 has the significant spectral weight of the vertical bar 3d(9)4f(3)> final state in Pr 3d core-level spectrum. We interpret that the observed prominent intensity just below EF arises from a Kondo resonance due to the strong hybridization between the Pr 4f and conduction states. (c) 2005 Elsevier B.V. All Rights Reserved.