Abstract: The stanch bleeding composition of Cacumen Biotae——quercitrin was separated by polyamide column chromatography and by preparative TLC, and then used as standard for its determination in the crude drug——Cacumen Biotae by HPLC YWG-C₁₈H₃₇(7～9μm)ODS was used as the stationary phase and KH₂PO₄(0.01mol/L) -methanol-acetic acid (55:45:15) as the mobile phase. Detection was performed by UV at 260 nm.The leaf and branch of Biota orientalis (L.) Endl. contain 0.15～0.20% and 0.01% of quercitrin, other parts of the tree do not contain this component.