A method of multiplicating seedlings of a plant wherein tissue culture is applied to tissue pieces or cultured cells of the plants belonging to Papaveraceae, Solanaceae except for Torenia , Umblliferae, Rosaceae, Liliaceae except for Lilium, Compositae, Geraniaceae, Cucurbitaceae and Gramineae by using a medium containing at least on compound selected from the group consisting of calcium ionophore, cyclic AMP and polyamine. Plant body of high quality can be cultured in a great amount of a higher efficiency from the tissue pieces or cultured cells of plants, as compared with the conventional process.
