Thermoassociative copolymer(PAVD) was synthesized by the micellar copolymerization technique using sodium 2-acrylamido-2-methylpropane sulphonate(NaAMPS),N-vinylcaprolactam(VCL) and divinyl benzene(DVB) as raw materials.PAVD was characterized with FT-IR and 1H-NMR.Elementary analysis was used to determine the polymer composition.GPC measurement was used to show the weight average molecular weight.The thermoassociating behavior of PAVD was investigated in the aqueous solution.The effect of the polymer concentrations,the salt addition on the thermo-thickening behavior were further studied.The results indicate that PAVD shows sharp thermothickening properties when the mass concentration is up to a certain value.And the effect of thermothickening properties is strengthened with the increase of mass concentration and external salt concentration.Results from the anti-aging test show that the copolymer aqueous solution exhibits the excellent thermal stability at 80 ℃.