Higher plants produce a variety of secondary metabolites, many of which are isolated and used as pharmaceuticals. Plants containing these secondary metabolites are also important sources of ingredients for herbal medicines. In our laboratory, we collect Glycyrrhiza and Ephedra, two species of medicinal plants that are the base materials for important herbal medicines, and conduct research on them. In addition to analyzing the enzyme genes involved in the biosynthesis of bioactive components produced by these plants, we are also conducting research to biosynthesize useful substances using these genes. Furthermore, we are conducting a comparative analysis across plant lines that exhibit various mutations at the component level and the gene level, and we are conducting research aimed at “breeding” the raw materials for herbal medicines.