Radioisotope methods have been analyzed to study the dispersion of sulfur in rubber compounds. The radioactivity of the S-35 isotope introduced into rubber compounds has been measured by volumetric and surface methods. These methods can be applied to investigate physical and chemical processes in rubber and to optimize technical conditions of tire production. It was found that the radioisotopic methods can be used in the studies of sulfur blooming. Experimental data of the effect of mixing and the storage temperatures of the rubber compound on theses processes are presented. Rubber compounds containing soluble sulfur, insoluble Crystex sulfur, and T-accelerator were made for such investigations.