Steady viscous flow and dispersion properties of aqueous suspensions containing monodispersed silica microspheres of 0.9 μm were studied with special emphasis on the effect of PVA addition as a function of pH. Larger amount of PVA adsorption, observed at lower pH, always favored better dispersion and lower apparent viscosity. An apparent median particle size of the flocs in the stagnant suspension was mainly dominated by electrostatic repulsion and accordingly by pH. While the zeta potential was determined solely by the surface species of the particles coated with either Al2O3or ZrO2, silica substrate was suspected to affect the adsorption behavior of PVA on the silica particles, coated particularly by Al2O3.