A method of manufacturing a purified product of a liquid medium-chain alkyl-modified polydimethylsiloxane that is free of a specific (unpleasant) odor and is practically odorless, the method comprising the steps of: [A] synthesizing a liquid medium-chain alkyl-modified polydimethylsiloxane by carrying out a hydrosilylation reaction between a hydrosilyl-containing polydimethylsiloxane and an ±-olefin with 4 to 18 carbon atoms； and [B] subjecting a crude product of the liquid medium-chain alkyl-modified polydimethylsiloxane obtained in preceding step [A] to an odor-removing treatment by conducting a hydrogenation reaction which is carried out in the presence of a hydrogenation catalyst.
