Amphoteric polyacrylamide was prepared by dispersion polymerization with acrylamide, dimethylaminoethyl methacrylate methyl chloride, and acrylate acid as monomers, ammonium sulfate (AS) aqueous solution as a reaction medium, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as a stabilizer, and 2,2′-azobis(2-amidinopropane) dihydrochloride as an initiator. The influence of particle morphology on AmPAM dispersion and other factors and polymerization were investigated. Three crucial factors responsible for particle morphology are the dispersant concentration, sodium chloride concentration, and ionic degree of terpolymer. The ammonium sulfate concentration had relatively less of an effect on particle morphology, but a suitable concentration was necessary to obtain a stable dispersion system. A higher concentration of PDMC could yield more uniform and spherical particles during dispersion polymerization. A small amount of sodium chloride can decrease particle size and dispersion viscosity. These four factors heavily influenced the viscosity of polymer dispersion, and they had a large effect on the intrinsic viscosity of AmPAM except for the AS and NaCl concentration. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E212-E220, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21264 [ABSTRACT FROM AUTHOR]