Cultivation of Bupleurum falcatum L. and determination of saikosaponins by high-performance liquid chromatography (HPLC) were studied. The yueld of dry roots decreased, while the weight of each root increased, as the cultivation period became longer in one-year-old plants. The yield and the weight of each root were shown to be higher in two-year-old plants than in one-year-old plants. The number of plants that survived, however, was greatly decreased by two-year cultivaion. By clipping the aerial part of the plant at the height of 50 or 70 cm, the weight of each root was increased, while the yield of the root was decreased. Mulching of the field with transparent or black vinyl sheet increased the weight of root while silver sheet was ineffective. The content of saikosaponin a or d (SA or SD) was higher in one-year- than in two-year-old plant. The correlation between the root weight and the content of SA or SD was poor. However, a close correlation was found between the contents of SA and SD in the same root.