Abstract:A cotton cadinene synthase gene was transferred into Artemisia annua L. via Agrobacterium rhizogenes. The cotton cDNA cad-C14 was placed in binary vector under the 35S promoter. Leaf explants were infected with Agrobacterium rhizogenes 15834 containing binary vector to induce the hairy roots. 121 hairy root lines with rapid growth were established. A concentration of 20 mg/ L kanamycin was added in order to select the transformed hairy roots. 12 hairy root lines were selected, which were resistant to kanamycin. Polymerase chain reactions and Southern blotting revealed that 3 % of the hairy roots (four hairy root lines ) contained the foreign gene. The results of RT-PCR suggested that the foreign CAD gene of the transgenic hairy root had expressed at the transcriptional level. An efficient Agrobacterium rhizogenes-mediated transformation system of Artem/s/a annua was established.