A method of introducing a symbiotic fungus producing one chanoclavine as a final metabolic product into a plant, includes the steps of isolating symbiotic fungi from naturally existing plants, artificially cultivating the isolated symbiotic fungi, introducing the cultivated symbiotic fungi into target plants, infecting the target plants with the introduced symbiotic fungi, determining whether the introduced symbiotic fungi infecting the target plants produce the chanoclavine as the final metabolic product, and selecting the target plants which produce the chanoclavine as the final metabolic product.