To provide an industrial production process for cycloalkyl-substituent- containing silane or polyorganosiloxane.

This process is for producing the cycloalkyl-substituent- containing silane or polyorganosiloxane in an industrial scale and includes a step (A) where the fluid mixture of a Raney nickel catalyst and the carrier fluid are charged in the reactor, a step (B) where the carrier fluid is removed from the Raney nickel catalyst in an inactive atmosphere, a step (C) where the reactants comprising a silane or polyorganosiloxane bearing at least one aromatic hydrocarbon group and hydrogen are charged in the reactor containing the Raney nickel catalyst and a step (D) where the catalyst, the silane or polyorganosiloxane and hydrogen are heated at a temperature enough to form the objective silane or polyorganosiloxane bearing cycloalkyl substituents.