Water dispersion of polyurethaneurea anionomer based on polyurethane synthesized by using "one-step process" and water dispersion of polyurethaneurea anionomer based on polyurethane synthesized by using "two-step process" were prepared. Spectra of C-13-NMR proved that the distribution of the hydrophilic monomer units along the macromolecular chain resulted from the latter process was more uniform than that by the former process. Uniform distribution of hydrophilic monomer units led to smaller average size and polydispersity of the polyurethaneurea particles dispersed in water, as well as higher stability of the water dispersion. (c) 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 634-640, 2007