Abstract: The modeling of the dynamics of adsorption of an organic dye (Rhodamine B) onto natural clay on a fixed bed from aqueous solutions was studied. The application of different models to describe the breakthrough curve shows that the models of Clark, Yoon and Nelson and Thomas give better results for the operating conditions. The Bohart and Adams model describes only the initial part of the breakthrough curve. The study of variation of parameters of the mass transfer zone for different operating conditions shows that the rate of mass transfer area increases with increasing initial concentration. The rate of saturation and the partial ability of the bed do not depend on operating conditions.