The surface modification of the polymers has been studied in RF-discharge. A plasma-chemical model is presented, describing the alteration of the adhesion work and the wetting contact angle of the treated materials. It is presumed that the adhesion work can be expressed by its volume and surface components. In the first approximation, only the surface adhesion work is changed in the course of the plasma treatment and it is due to creating of two common functional groups. We suggest a basic system of kinetic equations for quantitatively determining these groups. The system is solved analytically. This gives possibilities to obtain the analytical solutions of the adhesion work and the contact angle as a function of the time of treatment. (c) 2006 Elsevier B.V. All rights reserved.