Abstract: Five compounds, B₁, B₂, B₃, B₄, B₅were obtained from the ether extract of Bupleu-rum Sibiricum Vest by means of silica gel, alumina and Sephadex LH-20 column chroma-tographies. The structures were elucidated on the basis of spectral analyses (IR, UV, CD, EIMS, ¹HNMR and ¹³CNMR, DEPT, ¹H-¹H COSY, ¹H-¹HNOESY and single crystal X-ray analysis) and chemical reactions. The compounds were identified as : Z,Z' -6, 7,3',8' -dili-gustilide(B₁), Z, Z' -6, 7, 3a', 6' -diligustilide (B₂), cis-6, 7-dihydroxyligustilide (B₃), preg-nenolone(B₄) and vanillin(B₅). Compound Bj is a new compound. The others four, B₂,B₃,B₄, B₅were isolated from the Bupleurum genus for the first time.

Key words: Umbellif erae, Bupleurum Sibiricum Vest, Diligustilide