Abstract: Anew steroidal saponin, m. p. 310℃, [a]₂₀^D= -90.0℃, was isolated from 70% alcoholic crude saponin extract of the rhizome of Smilax menispermoides D. C. by silica gel column chromatogra-phy and further purified by Sephadex LH-20. Its structure was determined as : (25D) spirost-5-en-3β, 17α,27-triol-3-O-[β-L-rhamnopyranosyl (1-2)] [a-L-rhamnopyranosyl (1-4)]-α-D-glucopyra-noside by means of IR, MS, ¹³C NMR, DEPTand chemical methods.

Key words: Smilax menispermoides, Liliaceae Family, Steroidal Saponin