Adsorption equilibrium data for pure carbon dioxide and ethane on STH-2 graphitized carbon black were measured by a volumetric method. The experiments were carried out over the temperature range (253.2 to 303.2) K and the pressure range (0 to 4) MPa. The relative pressure p/po and adsorption amount n have been adopted to express adsorption isotherms, and the experimental data present a generalized adsorption isotherm over the research range. On the basis of this generalized isotherm, a method of predicting gas adsorption equilibria was explored. The prediction accuracy is satisfactory. In addition. analysis of the BET equation provides proof that the generalized adsorption isotherm p/po similar to is reasonable.