Abstract: Results of turbidimetry study of aggregate stability of binary SiO₂–ZrО₂ sol and its components in 10^–3–10^–1 M KCl solutions at рН 3.4 when ZrO₂ particles have a high positive charge and SiO₂ particles are slightly (close to zero) negatively charged are presented. The ratio of numerical concentrations of sol particles ZrO₂ to SiO₂ was 7.8 : 1. It was found that in binary SiO₂–ZrО₂ sol both the process of heterocoagulation (mutual coagulation) of sols and coagulation of the same oxide particles occur throughout the studied range of KCl concentrations. The way of differentiation of processes of dissimilar SiO₂ and ZrO₂ particles heterocoagulation and coagulation of components is proposed. It is shown that at pH 3.4 the increase in the concentration of KCl solutions in binary SiO₂–ZrО₂ sol leads to a decrease in the intensity of the process of ZrO₂ and SiO₂ particles mutual coagulation, which is explained by the decrease in the radius of action of attraction of dissimilar particles.