There is provided a method of synthesizing an organosilicon compound. This method comprises polymerizing, as a starting material, allyl-(4-alkynyl-phenyl) silane represented by the following general formula (3) in a solvent selected from methylene chloride, chloroform, carbon tetrachloride and 1,2-dichloroethane and under the presence of hafnium tetrachloride to obtain an organosilicon compound represented by the following general formula (1). ##STR00001## (wherein R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group, R's may be the same or different and are individually an alkyl group having 1 or 2 carbon atoms or a phenyl group, and n is an integer of 4 to 2500).