The stages of the formation of metal hydroxide particles in water medium were described. The first stage is the formation of complexes between the stabilizer and metal ion or of metal polyions containing a few metal ions. Dependence between the number of metal ions in polyion and its charge on the pH is described. The second stage is the formation of the metal hydroxide particles by the aggregation of polyions or their adsorption on/in the stabilizer. The distribution of the polyion number in the particles in polyion aggregation is described by the equation p(k)=k(k(s-1))((k 1))/k(s)(k) and in polyion adsorption on/in the stabilizer particles is more narrow and is described by the equation p(k) =exp(-k(s))k(s)(-k)/k!, where k and k(s) are the number and the average number of polyions in the particle. (C) 2004 Published by Elsevier Inc.