1. The dipole moments of nine organosilicon compounds were measured. 2. An estimate was made of the atomic polarization for symmetrical compounds containing two silicon atoms, separated by methylene bridges, and for compounds containing silicon in four- and five-membered rings. 3. Taking into account the atomic polarization, the dipole moments of 1-phenyl-1-methyl-1-silacyclobutane, 1-benzyl-1-methyl-1-silacyclobutane and 1-chloro-1-methyl-1-silacyclobutane were calculated. .