In this work is presented a systematic study, at laboratory scale, of the chemical transformations that occur when a vacuum residue is submitted to a catalytic reforming process with steam. The vacuum residue sample used comes from Crude Jobo-Morichal and is upgraded with a novel ultradispersed catalytic system, mainly composed of a water/oil emulsion where water-soluble precursors salts are dissolved in the discontinuous aqueous phase. For the preparation of the ultradisperse catalysts, organic and inorganic catalytic precursors were used. Additionally, mono, bi and tri metallic formulations were prepared combining transition and alkaline metals. The catalytic reaction is executed in water steam presence, temperatures between 400-450 degrees C and pressures in the range of 160-200 lb/pulg(2). The vacuum residue conversion to light fractions in the presence of the different ultradispersed catalytic formulations is quantitatively higher than those obtained for the corresponding thermal process, performed in the absence of catalyst and under the same experimental conditions. Furthermore, with the organic catalytic precursors the bottom product obtained have better reological conditions than those obtained when inorganic precursors are used, due to the existing chemical affinity between the families of the former ones and the hydrocarbon feed used. Alike, when tri-metallic catalytic were used the bottom product obtained had better characteristics, in comparison with the tests where a catalytic precursor composed mainly by two transition metals was used,