PROBLEM TO BE SOLVED: To extremely efficiently cultivate high-quality Undaria pinnatifida. SOLUTION: This method for cultivating the Undaria pinnatifida comprises a step of cutting the raw Undaria pinnatifida and collecting somatic cells, a sterilizing step of sterilizing the collected pieces 1 of the Undaria pinnatifida, a culturing step of dipping the sterilized pieces 1a of the Undaria pinnatifida in a culture solution 3, irradiating the pieces 1a of the Undaria pinnatifida with light and culturing the pieces 1a of the Undaria pinnatifida, a pulverizing step of pulverizing the cultured cells cultured in the culturing step and an adhesive step of arranging an adhesive material 4 for making the cultured cells adhere in the culture solution 3 containing the pulverized cultured cells dispersed therein and making the cultured cells adhere to the adhesive material 4 and a growing step of connecting the adhesive material 4 to a growth material, stretching the growth material in the sea and growing the Undaria pinnatifida.
