Four new alkaloids, gardneramine, C₂₃H₂₈O₅N₂, gardnutine, C₂₀H₂₂O₂N₂, gardnerine C₂₀H₂₄O₂N₂·H₂O, and hydroxygardnutine C₂₀H₂₂O₃N₂ were isolated from a japanese plant, Gardneria nutans SIEB. et Zucc. (japanese name "Hohrai-kazura"), and those alkaloids were characterized.