Triterpene saponins (ginsenosides) are main bioactive compounds in Panax ginseng. From mevalonic acid pathway, the isoprene units was synthesized that is precusor of triterpene saponin. This study provides the complete nucleotide sequence of the full-length cDNA involved in mevalonic acid biosynthesis pathway. We had a full-length cDNA sequences as followed; HMGS (1944bp, 1407bp ORF), HMGR (2120bp,1728bp ORF) and MDD (1760bp, 1263bp ORF) with partial poly (A). We were used real time PCR and High Performance Liquid Chromatography (HPLC) to analysis the expression level of the gene involved in MVA pathway and to ginsenoside contents, respectively. All cloned genes are constitutively expressed in all tested tissues but at different levels with the highest expression in fine roots. But ginsenoside contents is highest in leaf > fine root> lateral root > red berry> main root > petiol > stem. After treantment of methyl Jasmonate (MeJA), MVA pathway genes are highly expressed and ginsenoside contents was high at 72h.