Experimental studies have been made on the isothermal fixed-bed adsorption of benzene, toluene and p-xylene vapors, and their binary and ternary mixtureson activated carbon. From the breakthrough curve analysis, the equilibrium relationships for pure-, binary- and ternary-adsorption on activated carbon were obtained at 30℃. It was found that the adsorption equilibria of aromatic VOCs on activated carbon can be expressed by the Freundlich eqaution and the adsorbed solution theory. Also, the experimental breakthrough curves can be predicted by the mathematical model with the linear driving force (LDF) approximation for intraparticle diffusion.