The invention provides a particle dispersion for an electrostatic image-developing toner containing either polycondensation resin particles, which are prepared by polycondensation of polycondensable monomers in an aqueous medium, or condensation compound particles, which are prepared by dehydration condensation of a condensable compound in an aqueous medium. The particles have a median diameter of approximately 0.05 to 2.0 .mu.m. A dispersion containing the polycondensation resin particles is produced by dispersing resin particles, aggregating the resin particles, and coalescing the aggregated particles by heating. A dispersion containing the condensation compound particles is produced by dispersing resin particles, dispersing condensation compound particles, aggregating the resin particles and the condensation compound particles in a mixture dispersion, obtained by mixing the dispersion of the resin particles and the dispersion of the condensation compound particles, and coalescing the aggregated particles by heating.