ratios of organosilyl monomers was carried out at 60-70C. The compositions of the polymers were determined by FT-IR spectroscopy and 1 H-NMR. The glass transition temperature (Tg) of the polymers was determined calorimetrically. The study of DSC curves showed that incorporation of monomers with cyclic units in polymer chains increases the rigidity of terpolymers and the Tg value is subsequently increased