The adsorption of sodium polystyrene sulfonate (PSSNa) on kaolin from aqueous NaCl solutions of various concentrations at 30℃．45℃ and 60℃ has been studied．In the absence of NaCl，the amount of adsorption was found to be independent of tempera-ture. i.e．heat of adsorption，△H=O．The shape of adsorption isothel m indicates the presence of multilayer adsorption and sonic correlation between the isotherm and the nsp／C～C curve of PSSNa solution has been found．In aqueous NaCl solution，heat of adsorption is still equal to zero，but the amount of adsorption increases considerably，and the isotherm does not show multilayer adsorption．The crystalline indices of kaolin was found unchanged after the adsorption of PSSNa．It is supposed that the adsorption of PSSNa on kaolin is physical in nature．The multilayer adsorption and the increase of adsorption by NaCl may be attributed to the presence of phenyl groups in the side chain of PSSNa and the coiling of polyanion PSS-．The mechanism of adsorption has been discussed．