Monte Carlo simulation was applied to calculate the static properties of chain molecules (C28H58, C30H62, and C32H66) in Supercritical ethane at 308.15 K. Chain molecule and ethane were treated as a linear chain with many sites and single site molecules, respectively. The potential functions proposed by Jorgensen et al. were used for the interaction energy between pair sites and the rotational potential energy of valence bonds. The residual chemical potential was calculated by the isothermal-isobaric Kirkwood method in order to calculate the solubilities of chain molecules in supercritical ethane. An intermolecular interaction parameter between ethane and chain molecule was introduced to fit the calculated solubilities to the literature data. Furthermore, the mean-square end-to-end separation, the mean-square radius of gyration, the probability density distribution of rotational angles of the chain molecules, and the radial distribution function were reported as fundamental knowledge of the microstructure of the chain molecule in supercritical ethane.