Experimental results are presented on polymer adsorption investigations of two-phase solutions where simultaneous adsorbent contact occurs with both the phases. Adsorption measurements were performed from highly concentrated two-phase solutions (C much greater than C*) of the incompatible ternary system polystyrene (PS)-poly-(butyl methacrylate) (PBMA)-CCl4. Preferential PS adsorption was observed as compared with PBMA in the whole concentration range. Addition of fumed silica to highly concentrated polymer blend solutions leads to increasing of PBMA concentration, which is probably caused by the improvement of thermodynamic compatibility of PS and PBMA in the presence of adsorbent. Using NMR spectroscopy, the fraction of immobilized polymer segments was determined and total adsorption layer thickness was calculated. Great values of adsorption and adsorption layer thickness with small fraction of segments anchored to the surface are caused by adsorption of macromolecular aggregates. The results obtained are explained by the continuous change of the thermodynamic quality of the "mixed" solvent, which governs the phase separation processes in solutions of two incompatible polymers.