Amphoteric polyacrylamide (AmPAM) was prepared successfully through dispersion polymerization with acrylamide and amphoteric monomer 3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate in ammonium sulfate solution, using 2,2'-Azobis(2-methylpropionamide )dihydrochloride as initiator and poly methacrylatoethyl trimethyl ammonium chloride ( PDMC ) as stabilizer. The influences of concentration of stabilizer, inorganic salt and initiator ，monomer mass fraction and monomer ratio on dispersion polymerization were investigated. The optimum reaction conditions were ascertained as follows: ammonium sulfate concentration was from 22.3 to 26.3wt%, stabilizer concentration was from 0.195 to 0.248 g•(g(monomer))-1, the monomer ratio n (AM): n (DMAPS) was 9:1, the monomer mass fraction was 14%, the amount of initiator was 4.5×10-4 g•(g(monomer))-1. The structure of AmPAM was characterized by infrared spectrum and 1H nuclear magnetic resonance (1HNMR).