Dried whole herb of Chrysosplenium japonicum Makino was extracted with methanol, the extract was treated with lead acetate, and a glycoside was obtained as yellow needles, m.p. 203° (melting once at 160°) in 0.7% yield. Its molecular formula agreed with C₂₄H₂₆O₁₃⋅1 1/2H₂O; [α]_D²³: -50.7°. Hydrolysis with 10% sulfuric acid afforded 1 mole each of a genin as yellow needles, m.p. 158-159°, C₁₅H₇O₅-(OCH₃)₃⋅1 1/2H₂O, and glucose. The glycoside was named chrysosplenin, and the genin, chrysosplenetin. Demethylation of chrysosplenetin gives quercetagetin, so that chrysosplenetin is quercetagetin trimethyl ether. Decomposition of chryso-splenetin with 3% hydrogen peroxide gives vanillic acid, and with 15% potassium hydroxide, vanillic acid and 4, 5-dimethoxyresorcinol are formed. Methylation of chrysosplenetin affords a dimethyl ether, m.p. 157-158°, and a trimethyl ether, m.p. 142-143°. The dimethyl ether agrees with the formula C₁₅H₅O₃(OCH₃)₅⋅1 1/2H₂O, and was found to be quercetagetin 3, 6, 7, 3′, 4′-pentamethyl ether by mixed fusion. It follows, therefore, that chrysosplenetin is quercetagetin 6, 7, 3′-trimethyl ether. The structure of chrysosplenin is chrysosplenetin-3 (or 5)-glucoside.