The surface composition and electronic structure of tungsten carbides prepared by directsynthesis and carburization of white tungstic acid were studied with X-ray photoelectron spectros-copy. The experimental results show that WO_3 and free carbon are present on the surface of thecarbides. For the high surface area tungsten carbide prepared from white tungstic acid a largeextent of oxygen insertion into the crystal lattice was observed. Measurements of the binding energiesof the W_(47/2), C_(1s) and O_(1s) core levels indicate that charge transfer is from the W to the C and Oatoms, forming W_(5d)-C_(2p) and W_(5d)-O_(2p) bonding. The catalytic behavior of the tungsten carbides inhydrocarbon conversion reactions is mentioned and compared with Pt catalysts. The surface composition and electronic structure of tungsten carbides prepared by directsynthesis and carburization of white tungstic acid were studied with X-ray photoelectron spectros-copy. The experimental results show that WO_3 and free carbon are present on the surface of thecarbides. For the high surface area tungsten carbide prepared from white tungstic acid a largeextent of oxygen insertion into the crystal lattice was observed. Measurements of the binding energies of the W_ (47/2), C_ (1s) and O_ (1s) core levels indicate that charge transfer is from the W to the C and Oatoms, forming W_ (5d) -C_ (2p) and W_ (5d) -O_ (2p) bonding. The catalytic behavior of the tungsten carbides inhydrocarbon conversion reactions mentioned and compared with Pt catalysts.