A mathematical model of polymer adsorption kinetics from a solution onto a solid/liquid interface in the diffusional field is suggested. The kinetic model takes into account the influence on adsorption and desorption rates of polymer molecular mass, hydrodynamic regime, and surface coverage of the polymer. The correspondence of the kinetic model to experimental data on polyethylene oxide adsorption onto a silica surface from water in stagnation point how is shown. The surface area blocked by a macromolecule and the fraction of solvent in a saturated adsorbed layer have been calculated. Values are found for the rate constants of adsorption and desorption as well as for the constants of adsorption equilibrium for poly(ethylene oxide) with molecular mass from 7.1 x 10(3) to 847 x 10(3).