Abstract:A polyether grafted copolymer of acrylic acid/sodium methylacrylsulfonate,which can be used as superplasticizer,was prepared by water solution polymerization using acrylic acid,sodium methylacrylsulfonate and acrylic acid-polyoxyethylene ester as monomers and ammonium persulfate as initiator.The influence of dosage of monomers and length of side chain on the properties of water-reducer are discussed and the suitable technologic conditions are determined.The structure of copolymer was characterized by FT-IR spectrum.