The bactericidical and actinomycetical properties of diethoxysilanes and their polymers on the base of polycyclic bisphenols were studied. Diethoxy (organo) thiienylsilanes were obtained by esterification of the approp[riate dichlorosilances with the excess of absolute ethanol and in the presence of pyridine in dry toluene. The synthesized diethoxysilanes are transparent substances with a characteristic slight smell. They are readily soluble both in polar and nonpolar organic solvents. The structure of the synthesized compounds was determined by the IR and H-NMR spectra.