A batch experiment was conducted to study the adsorption of copper, lead, cadmium and nickel by bentonite in single component and binary systems. The results showed that adsorption capacity of copper and lead are higher than that for cadmium and nickel. The order of adsorption capacity was as follows: Pb²⁺>Cu²⁺>Ni²⁺>Cd²⁺. The single ion equilibrium data were fitted to Langmuir and Freundlich isotherms. The adsorption isotherms in binary-component systems showed that there were competition between copper and lead, copper and cadmium, copper and nickel. Adsorption of copper was depressed by the presence of lead in the adsorption solution, but adsorption of lead was depressed little by the presence of copper. Adsorption of copper was also depressed by the presence of nickel and cadmium, however adsorption of nickel and cadmium were completely depressed by the presence of 100 mg/L Cu²⁺. Equilibrium data for the binary adsorption of copper and lead were analyzed by using Ideal-Adsorption-Solution (IAS) and Langmuir-Competitive- Adsorption models, but these equations weren’t fitted to data for the mixed solutions. The Modified LCA model fits the binary adsorption equilibrium data satisfactorily and adequately. Finally, binary-component competitive adsorption of copper and lead was simulated by Modified LCA model in computer.