Abstract: cDNA encoding pleiotropic drug resistance(PDR) gene， whose length was 693 bp， was amplified from Eleutherococcus senticosus，by means of polymerase chain reaction(PCR) with degenerate oligo nucleotide primers， the gene has been deposited in GenBank under accession number KC473536. It encoded a protein of 231 amino acids belonging to PDRs nucleotide binding domain. In comparison with E.senticosus PDR with those of Populus trichocarpa， Ricinus communis and Oryza sativa on the amino acid sequence， the amino acid homology was 8874%， 9004% and 8831%. The expression of PDR in different organs of E.senticosus in various growing periods was detected by RTPCR， and E. senticosus saponins content was measured by spectrophotometry method， the results showed that PDR gene expressed in the whole growing periods of E.senticosus， which was consistent with the characteristic of saponins formation in the whole growing periods， and the correlation of the two was not significant. The characteristic of high expression of PDR gene in leaf and petiole was consistent with the phenomenon that saponins were only found in leaf， which showed significantly positive correlation (P<005)．

Key words: Eleutherococcus senticosus, pleiotropic drug resistance transporter, cloning, expression analysis, saponins