CNDO/2 calculation for atomic charges, Wiberg bond orders and adsorption energies of CO molecules on the cluster model whose Si/Al ratio varied were carried out. The data for the normal cluster and dealuminated cluster were compared. Decationization energies of the cations increased with the charge densities of cation and number of aluminum involved. Adsorption process of CO on the monovalent cations such as H⁺, Li⁺, Na⁺ and divalent cations, Be²⁺, Ca²⁺, and Mg²⁺ was supposed to be occurring by the donation of non-bonded electrons from CO. The decationization energies of cations obviously decreased by the dealumination process. Adsorption energies of CO on the cations generally decreased as the dealumination took place except the case of H⁺ and Na⁺.