An experimental determination of the solubilities of solid mixture in supercritical (SC) fluids was made. By use of a continuous gas flow apparatus, the solubilities of naphthalene + phenanthrene in SC-CO2, phenanthrene in SC-fluoroform (CHF3), and naphthalene + phenanthrene in SC-fluoroform have been measured at 308.2 K and 4.8 to 28 MPa, The solubilities of a component for the two solid-mixture system have been enhanced as much as 130% higher than that for a single pure solid system at the same temperature and pressure. For the naphthalene + phenanthrene mixture, the selectivities between these components in fluoroform were higher than those in carbon dioxide, Finally the experimental solubilities were correlated using not only three equations of slate but also tn?ro empirical density dependent equations.