Two new C_(21) steroidal constituents, named otophylloside A(Ⅳ) and otophylloside B(Ⅴ), have been isolated from the roots of Cynanchum otophyllum Schneid, whose structures have been analysed in this paper by using X-ray crystallography and spectrometric data (UV, IR, ~1H- and ~(13)C-NMR, MS) and chemical reaction. They were found to be active against epilepsy, Ⅳ and Ⅴ can protect rats from a udlogenic seizures(AS) and its ED_(50)=10.20mg/kg. Two new C 21 steroidal constituents, named otophylloside A (Ⅳ) and otophylloside B (Ⅴ), have been isolated from the roots of Cynanchum otophyllum Schneid, whose structures have been analyzed in this paper by using X-ray crystallography and spectrometric data (UV, IR, ~ 1H- and ~ (13) C-NMR, MS) and chemical reactions. They were found to be active against epilepsy, Ⅳ and Ⅴ protect protectors from a urogenous seizures (AS) and its ED 50 ) = 10.20 mg / kg.