Abstract Eya, H., Iwai, Y., Fukuda, T. and Arai, Y., 1992. Monte Carlo calculation of solubilities of high-boiling component in supercritical carbon dioxide. Fluid Phase Equilibria, 77: 39-51. The test particle method proposed by Widom was applied to calculate the solubilities of naphthalene in supercritical carbon dioxide at 308.15 and 328.15 K. The Lennard-Jones (12-6) potential was used as the intermolecular potential and the Berthelot mixing rule was adopted for unlike molecular pairs. The calculated solubilities are in general higher than the experimental values of solubilities. However, by introducing an intermolecular interaction parameter between carbon dioxide and naphthalene, the calculation results showed good agreement with the experimental values.