Methyl jasmonate(MeJA) treatment promotes the plant secondary, especially triterpene saponin which is main compounds in Platycodon grandiflorum. We were performed 5,760 expressed sequence tags from MeJA treated hairy root. Total number of ESTs are 2,536 (811 contigs and 1,725 singletons) among them 2,299 are pass the annotation. The most abundant transcript were encoding fatty acid desaturase (FAD) and lots of secondary metabolite transcript were observed. Four MVA pathway genes (HMGS, HMGR, MK, MDD) and one MEP pathway gene (IDI) are identified. The unigene were classified into three major functional categories by standard GO (Gene Ontology) - cellular component, molecular function and biological process. In this study we were cloned four genes from ESTs : HMGS (1401bp ORF), MK (1167bp ORF), MDD (1254bp ORF), IDI (909bp ORF)