The copolymer of PAANa －co－PVP was prepared by copolymerization of acrylate and N －vinyl pyrrolidone，intiated with the NH_３· H_２ O／H_２O_２redoxy intiator．The structure of the copolymer was characterized via FTIR method．It is educed that the reactivity ratio of AANa（r_１） and NVP（r_２） is 3.296 and 0.808 respectively，by analyzing the reactivity ratio results calculated by mathematical methods of FR，KT and YBR， via the aid of the test results of element analysis．The extrinsic cytotoxicity of the copolymer was evaluated through the 3-4,5－dimethylthiazol －2－yl －2,5－diphenyltetrazolium bromide （MTT） reduction assay．It is found that the copolymer is biocompatible．

Two kinds of polymerizable vinyl quaternary ammonium salt, namely dimethyldiallyl ammonium chloride and trimethyldiallyl ammonium chloride respectively, were prepared via the SN ₂ nucleophilic substitution of the allyl chloride with the tertiary amine. The structure of the prepared quaternary ammonium salts were characterized through the methods of element analysis, FTIR, H ¹－NMR and C ¹³－NMR. Two kinds of polyampholytic superabsorbent polymer, which include CMCTS-g-(PAA-co-PDMDAAC) and CMCTS-g-(PAA-co-TMAAC) respectively, were prepared through graft copolymerization of prepared vinyl quaternary ammonium salt and acrylic acid onto the chain of carboxymethyl chitosan, initiated with persulfate and crosslinked properly. The structure of the superbasorbent polymer was characterized by FTIR. Influence of the pH value of the solution on the swelling ratio of the polyampholytic superabsorbent polymer was studied.