2-Vinyllhiolane-1,1-dioxide (Ia) and 2-vinylthiane-1,1-dioxide(Ib) have been prepared and polymerized with free radical initiators to obtain poly(sulfonyl-hex-2-enylene) (IIa) and poly(sulfonyl-hept-2-enyIene-co-2-vinylthiane-1,1-dioxide) (IIb), respectively, via a ring-opening mechanism. Structures of the polymers are supported by infrared and 1H-NMR spectroscopy. Poly(sulfonyl-hex-2-enylene) was insoluble in ordinary organic solvents, but soluble in concentrated sulfuric acid or trifluoroacetic acid, and was white amorphous powder, softening at 168°C. Degradation occurred at 294°C under N2. Ia copolymerized with certain vinyl monomers, such as ethyl acrylate, but its copolymerization behavior was different from those of normal vinyl monomers.