Abstract: The adsorption of SDS and PVP from their mixed solutions onto TiO₂and carbon black has been determined exprimentally. On the surface of TiO₂, the adsorption of SDS and PVP shows synergistic effects at low SDSconcentrations and antagonistic effects at high SDS concentrations. On the surface of carbon black, the adsorption of PVP and SDS shows to be merely competitive. The experimental results were discussed in terms of the complex formation between PVP and SDS, as well as by the polarity of the solid surfaces.