To prepare the solubilized asphaltene in water (SAW), the feedstock of hydroprocessing experiments, oxidation reactions were conducted in a 550 mL batch reactor in the presence of NaOH in aqueous phase. At 240 degrees C and 2 h residence time the asphaltenes conversion reached 80% with 50% yield to SAW. The characterization of solubilized asphaltene in water (SAW) revealed that it contains a wide range of carboxylic acids with various alkyl tails. The presence of carboxylate and carboxylic functional groups in the SAW structure was also confirmed with FTIR analyses. The catalytic hydroprocessing of SAW was studied in a 100 mL batch reactor with presulfided NiMo/gamma-Al2O3 catalyst. The hydroprocessing results at 320 degrees C and 3 h residence time for SAW prepared at different severities shows that higher oxidation temperature produces the lighter liquid hydrocarbons, which suggests the oxy-cracking of asphaltene through wet oxidation. Increasing the concentration of solubilized asphaltene in water increased solids formation in hydroprocessing from 12.5% for nonconcentrated SAW to 26% for 10 times concentrated solution. The hydrogen deficiency was evidenced in hydroprocessing of high concentrated SAW, where increasing the initial hydrogen pressure from 600 psig to 1000 psig suppressed the solid formation from 26% to 9.5%. Liquid products from hydroprocessing mainly consisted of two cyclohexyl fused hydrocarbons with higher selectivity to naphthenic and lower selectivity to aromatic compounds. Detecting CO2 as a major component in the gas phase in parallel with the results of GC/MS before and after hydroprocessing confirms that oxygen removal is dominated by decarboxylation.