Abstract:The plant Fritillaria unibracteata Hsiao et K. CHsia of the family Liliaceae is an elemental species of traditional Chinese drug "Chuan Beimu" in Chinese Pharmacopoeia. Four compounds(C, D, E,F) have been isolated from its medicinal part (dried bulb). The latter three compounds were identified as D/E cis(22R, 25s)-20- deoxy-3β,6β-dihydroxy-5α,14α, 17β-cevanine(D), β-sitcsterol (E), stearic acid and palmitic acid(F) by mean of spectroscopic methods. Compound D belongs to a new alkaloid of cevine group of isosteroidal alkaloids which is attributed to the characteristic constituent of this genus, named as songbeinine.