In this study, the developmental anatomy of the roots of Bupleurum yinchowense was studied using paraffin sectioning and fluorescence microscopy. The results show that (1) The root apical meristem of B. yinchowense is composed of promeristem and primary meristem. The promeristem are characterized by small size, closely arranged, dense cytoplasm and large nucleus, showing characteristics of typical meristem. (2) The primary meristem consists of calyptrogen, protoepidermis, ground meristem and plerome. During the development of the primary root structure, the protoepidermis forms epidermis, the ground meristem develops into cortex, and the plerome forms vascular cylinder, and the epidermis, cortex and vascular cylinder form the primary structure of the root. The primary xylem of B. yinchowense roots is diarch or infrequent triarch, and the development of which is exarch. The the root epidermal cell walls is characterized by thickening in the radial walls. (3) In the root secondary growth, the original cambium between the primary xylem and the primary phloem continue to divide and produce vascular cambium. The vascular cambium continuously produces secondary phloem outward and forms secondary xylem inward. At the same time, the pericyclic cells differentiate continuely and form the cork cambium, and the cork cambium forms the cork layer outward and the phelloderm inward. During the development process of the B. yinchowense roots, the secretory canals with different shapes and sizes are detected in the secondary phloem and pericycle tissue, both of which are secondary and schizogenous. The results showed that the structure of Bupleurum yinchowense root was similar to B. chinense and B. scorzonerifolium, but the thickening of the radial walls of the root epidermal cells, the distribution of wood fibers, the size and number of secretory canals and so on were different from other plants in Bupleurum, which could be used as an important basis for the classification and identification.