The present invention provides: a transformant for expressing cis-prenyltranferase and the Nogo B receptor in a host by introducing into the host a gene that codes for cis-prenyltranferase, which is thought to participate in polyisoprenoid synthesis, and a gene that codes for the Nogo B receptor； and a method for producing polyisoprenoids using the transformant. The present invention is a transformant in which cis-prenyltranferase and Nogo B receptor are caused to be expressed in a host by introducing into the host a gene that codes for cis-prenyltranferase and a gene that codes for the Nogo B receptor.
