AA TPEG AMPS polycarboxylate superplasticizer(ATS) was synthesized by introducing 2 acrylamide 2 methacrylic acid(AMPS) into the structure of traditional AA TPEG polycarboxylate(PCE). A study including adsorption and XRD experiments revealed that the adsorption of ATS on montmorillonite did not differ much from PCE. The adsorption capacity of ATS on the cement particles is less than that of PCE. However, the adsorption layer thickness and the absolute value of the zeta potential of ATS are larger than that of PCE. Therefore, ATS exhibites a good dispersion property in cement clay system.