This text is intended to present information about the medicinal value of the Codonopsis lanceolata, method for high frequency regeneration using different explants and to optimize the factors and conditions required for the gene transformation in Codonopsis lanceoalta which can be routinely used for genetic transformation. Further, ¿-TMT gene were introduced for improving the a-tocopherol contents in this plant. As a result, the a-tocopherol content increased in in aerial and subterrenian parts of the transformed Codonopsis lanceolata by over expressing the ¿-TMT gene. Antioxidant activities of transgenic and control plants using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) analysis and measurement of phenolic compounds, as well as photosynthetic performance were also investigated to ascertain the relationship between changes in the phytochemical profile and photosynthesis rate due to ¿-TMT gene overexpression in transgenic plants.