Radical polymerization and copolymerization of bis{3-[tris(trimethylsiloxy)silyl]propyl} fumarate (BSPF (1)) were investigated. The reactivity of BSPF in homopolymerization was found to be very low, and only low-molecular-weight poly(BSPF) was obtained in low yields. On the other hand, copolymerizations of BSPF with diisopropyl fumarate (DiPF) and di-tert-butyl fumarate (DtBF) proceed with moderate rates to give high-molecular-weight copolymers. The monomer reactivity ratios were determined to be as follows; r1 = 0,07, r2 = 0,87 for BSPF (M1) and DiPF (M2); r1 = 0,21, r2 = 0,67 for BSPF (M1) and DtBF (M2). The resulting copolymers are soluble in many common organic solvents. Tough and brittle films were obtained by solution casting of the copolymers of BSPF and DtBF. The copolymers exhibit excellent oxygen permeability.