Studies were presented on optimisation of the technique of precipiting magnesium silicate of high dispersion extent so that the obtained product would exhibit possibly best physicochemical parameters. Magnesium silicate was obtained by precipitation reaction using solutions of magnesium sulphate and sodium metasilicate. The variables included temperature, the ways in which the reagents were dosed and addition of modifying substances. Physicochemical parameters of the product were estimated, including bulk density, capacities to absorb water, dibutyl phthalate and paraffin oil, particle diameters, specific surface area and electrokinetic potential.