The NVT and mu VT ensemble MC techniques have been used for simulations of adsorptions in a slitpore from a binary mixture of benzene diluted in supercritical CO2, The LJ potential function is used for representing intermolecular interactions between CO2, benzene and surface carbon, A typical curve for adsorption of benzene shows a maximum at a pressure below the critical pressure of CO2 and then decreases with increasing pressure, The magnitude of maximum adsorption increases with increasing interaction energy between benzene and surface carbon, It has been shown that this adsorption behavior is attributable mainly to enhanced solubility in the supercritical CO2 and partly to the competitive adsorption of CO2, The adsorption of carbon dioxide increases linearly with pressure and the slit pore becomes full of CO2 molecules under supercritical fluid conditions, The local density profile of benzene in a pore is scarcely affected by CO2; however, the profile of CO2 is strongly affected by benzene molecules when they occupy the first monolayer near the wall.