Feverfew (Tanacetum partheniumL. Schulz Bip.) is a medicinal herb belonging to the Asteraceae which recently raised researcher’s attention due to its medicinal value and pharmacological activities, especially as a migraine prophylaxis agent and also for treatment of cancer. Parthenolide has a sesquite rpene lactone structure which is most likely synthesized through the mevalonic acid (MVA) pathway. Recently, it has been shown that there is cross a talk between the MVA and the MEP pathways through IDP (Iosopentenyl diphosphate) exchange as a precursor for the biosynthesis of different terpenes; hence, parthenolide biosynthesis could be affected by the MEP pathway as well. In the present work, the relative gene expression of two key genes of the MVA pathway, including 3 - hydroxy - 3 -methylglutaryl -coenzyme A reductase (HMGR) and germacrene A synthase (GAS) and two key genes of the MEP pathway including 1 -deoxy - D -xylulose - 5 -phosphate reductoisomerase (DXR) and hydroxy - 2 -methyl - 2 -(E) -butenyl4 -diphosphate reductase (HDR) were examined in leaves derived from the vegetative or generative phases, also in flowers using real time PCR. The results of our study showed that expression of these genes depend on the growth stage and genotype. Moreover, in which in the flowers and leaves derived from vegetative phase in different genotypes only the TpGAS gene expression showed a significant difference, while in the leaves derived of generative phase the relative gene expression showed a significant difference for TpHMGR, TpGAS and TpDXR.