A highly dispersed emulsion of an organosulfur compound is obtained by use of a coemulsification system of a surfactant, and an electrolyte, and a cosurfactant and optionally a hydrocarbon; such as a petroleum sulfonate with potassium chloride and hexyl alcohol. Conversion of organosulfur compounds into highly dispersed emulsions increases the reactivity of the organosulfur compound as a molecular weight modifier in an aqueous emulsion polymerization system and permits the efficient use of high molecular weight organosulfur compounds.