Anatomical, histochemical and phytochemical methods were used to investigate the structure, the localization and the content of total saikosaponin and saikosaponin-a in vegetative organs of Bupleurum scorzonerifolium Willd.Histochemical localization results showed that saikosaponin was distributed in vascular cambium, secondary phloem and partial parenchyma cells of secondary xylem in the root.In the stem, they were mainly distributed in epidermis and cortex, and in the leaf, they were mainly located in the epidermis and mesophyll.The phytochemical results showed that the total saikosaponin accumulated in the vegetative organs of B.scorzonerifolium, with higher content in roots and lower content in the aerial parts that included stems and leaves.As the root is the main medicinal organ of B.scorzonerifolium, the content of saikosaponin in different parts of the root was determined.It was found that the content of saikosaponin in "skin areas" was higher than that in xylem, and the content was higher in lateral roots than that in taproots.Based on these results, the crude drug that had thick "skin areas" and thin xylem was of top grade.Meanwhile, judging from the external characteristics of the drug, the one with an acerose taproot and more lateral roots was of high quality.The results offered theoretical bases for selecting medicinal material of high quality.