Abstract: By chloroplatinic acid as the catalyst, four new 1,3-bis(chloro-silyl)-propanes (A) were synthesized from the addition of organo-sili-con hydrides to allyl-silicon compounds. By the reaction of nine different (A) with hydrogen sulphide in the presence of pyridine eleven novel six-membered hetero-cyclic silicon sulphur compounds were obtained. Their physical constants were determined. The structures of the products have been proved by chemical and physical methods.