A plant shoot is cultivated in the presence of glutathione to induce rooting of the shoot. The cultivation in the presence of glutathione can be carried out by using a rooting medium which contains glutathione, or by contacting the shoot with a solution which contains glutathione. As the glutathione, it is preferred to use oxidized glutathione. By promoting rooting of plant shoots and increasing the rooting ratio thereof, the productivity of clone seedlings can be increased.
