An anti-clay agent AA-SAS was synthesized by acrylic acid (AA) and sodium allylsulfonate(SAS) to improve the adverse effects of the clay for concrete. The copolymer was analyzed by IR, GPC, TG and XRD. The effect of the copolymer on the workability of cement paste and concrete with different clay was investigated. The results show that the molecular weight of AA-SAS is smaller and the diffusion rate of which is faster than polycarboxylate superplasticizer. The copolymer can be adsorbed preferentially by the clay in the concrete, thus reducing soil adsorbing polycarboxylate superplasticizer. The copolymer has a good anti effect on bentonite, kaolinite, mica and Weihe clay. The workability of concrete is improved obviously while adding the copolymer. When the solid content of AA-SAS was 0.11% of the cementing material, the 0.5 h concrete slump and fluidity is improved by 15 and 90 mm, and the 1 h concrete slump and fluidity is improved by 20 and 100 mm. In comparison with polymer（AA-AM）synthesized previously, the copolymer AA-SAS shows better property on resisting clay.