The efficient method for the synthesis of o(m)-carboranylmethylsiloxanesby the Grignard reaction based on 1,2 (7)-bis(bromomagnesiummethyl)-o(m)-carboranes and 1-chloro-1,1,3,3,3-pentamethyldisiloxane was developed. As a result, 1-(1,1,3,3,3-pentamethyldisiloxanylmethyl)-2(7)-methyl-o(m)-carboranes, 1,2(7)-bis(1,1,3.3,3-pentamethyldisiloxanylmethyl)-o(m)-carboranes, exocyclic 1,2-(o-carborano)-4,6-bis(dimethylsilyl)-5-oxa-cycloheptane, 1,7-bis(chloro-1,1,3,3-tetramethyldisiloxanylmethyl)-m-carborane and the oligomer containing two 1,7-bis(dimethylsilylmethyl)-m-carborane units were obtained.