An anionic water-soluble copolymer, poly(acrylamide/4-carboxylamino-4-oxo-2-butenate) (PAAM/COB), was synthesized and used as a dispersion agent for BaTiO3 particles. PAAM/COB was prepared from acrylamide and 4-carboxylamino-4-oxo-2-butenate in basic conditions through free-radical polymerization. The structure of this copolymer was verified by IR and H-1-NMR spectra. We examined the dispersion effects of PAAM/COB by measuring the viscosity and sedimentation of BaTiO3 suspensions and by analyzing the particle sizes. The results indicate that this copolymer was indeed effective in dispersing the particles, for the resulting suspensions were less viscous, more stabilized, and contained powder with smaller particle sizes. (c) 2005 Wiley Periodicals, Inc.