The adsorbed solution model has been used to predict competitive adsorption equilibria of the solute and the active component of mobile phase in a normal-phase liquid chromatography system. The inputs to the calculations were the single adsorption isotherms accounting for energetic heterogeneity of the adsorbent surface and non-ideality of the mobile phase solution. The competitive adsorption model has been coupled with a model of the column dynamics and used for simulating of chromatography process at different mobile phase composition. The predictions have been verified by comparing the simulated and experimental chromatograms. The model allowed quantitative prediction of chromatography process on the basis of the pure-species adsorption isotherms.