Abstract: In order to clone cytochrome P450(P450)in Eleutherococcus senticosus, the primers were designed according to cDNA of the reported Panax ginseng and P. notoginseng. The full length cDNA of the E. senticosus P450 was cloned by RT-PCR, and analyzed the expression of P450 in different growth periods and organs of E. senticosus. The results showed that the full length of P450 was 1 410 bp, encoded a protein with 469 amino-acid residues, GenBank accession number KF498590. To compare the amino acid sequence of E.senticosus P450 with P. ginseng and P. notoginseng, the amino acid homology was 91.5% and 90.4%. P450 expressed in different growth periods and organs of E. senticosus, and the expression amount differed significantly(P<0.05). The highest content of the expression showed up when full opening flower stage, which was 1.26 times as much as that in the lowest at germination stage. The highest content of the expression was in the leaves which was 1.49 times as much as that of the lowest in young stem.