Novel poly(silylenemethylenes) have been prepared by the ring-opening polymerization of 1,3-disilacyclobutanes followed by a protodesilylation reaction with triflic acid. The silicon-aryl bond cleavage could be controlled by using different leaving groups, for instance phenyl-and para-anisyl substituents. The reactions of the triflate derivatives with organomagnesium compounds, LiAlH4, amines, or alcohols gave functional substituted poly( silylenemethylenes). Hydrosilylation reactions or reductive coupling with potassium-graphite led to organosilicon network-polymers, which may serve as suitable precursors for silicon carbide and Si/C/N-based materials. The structures of the polymers were identified by NMR spectroscopy (Si-29, C-13, H-1).