Abstract: Two steroid sapogenins were isolated from the rhizome of Reineckea yunnanensis W. W. Smith, a liliaceous plant collected in central and west Yunnan, China. One of which was identified as diosgenin and the other, which melted at 275—277℃, was found to have the formula C₂₇H₄₄O₄. The following derivatives of the latter compound have been prepared: (1) diacetate, C₃₁H₄₈O₆, m.p. 181—182%; (2) dibenzoate, C₄₁H₅₂O₆, m.p. 236—239°; (3) 23-bromo-sapogenin diacetate C₃₁H₄₈O₆Br, m.p. 196—199℃. The infrared absorption spectrum of this sapogenin exhibited the characteristic absorption band of normal spiroketal side chain, it was assumed to be a new saturated dihydroxysteroid sapogenin and was provisionally named Yunnanogenin.