Abstract: Fourteen constituents(V₁～V₁₄) were isolated from Veratrum stenophyllum Diels. Eight of them were identified as known compounds. Among the remaining constituents the structure of stenophylline A (V₃), B (V₆) and B₁-Chaconine (V₁₂) as well as partial structure of stenophylline C (V₁₀) and D (V₁₄) have been elucidated. Another one has not been identified. V₃,V₆,V₁₀ and V₁₄ are new compounds, V₁₂ has not been found previously in Veratrum plants. The weak alkaloid fraction of the plant and V₃ were shown to have significant activity in lowering blood pressure and heart rate on anesthetic cat.