The co-coking and coal extraction processes involve the solubilization of bituminous coal in a petroleum stream, i.e. DO or LCO. The coal solubilization in these non-pure solvents has not been study. If either of these processes is going to be scaled-up, it is important to predict the coal solubility in a given petroleum stream. This work intends to calculate the solubility parameter of LCO and DO. These parameters will be compared with the solubility parameters of the coals used in co-coking and coal extraction to predict the interaction solvent-coal. The chemical composition for LCO is about 75% di-aromatic and for the DO is about 85% tri-aromatic. The solubility parameter of a di-aromatic (naphthalene), is in the range of the calculated solubility parameter of LCO. For decant oil, the solubility parameter of anthracene was not found to make the comparison.