According to studies the peels of pomegranate is as a rich source of antioxidants, especially phenolic compounds and carotenoids. Carotenoids are the non-enzymatic antioxidants and considered to be the most powerful antioxidants. Plant carotenoids are essential to provide photoprotection in chloroplast-containing tissues. These yellow, orange, and red pigments also provide color to flowers, roots, and fruits, and they are precursors of the phytohormones abscisic acid and strigolactone. Developmental and environmental signals can regulate carotenoid gene expression thereby affecting carotenoid accumulation. Despite extensive research on pomegranate, no comprehensive study has been conducted on the expression of the carotenoid biosynthesis pathway genes. Therefore, the aim of this study was analyze the expression of some genes involved in the carotenoid biosynthesis pathway, such as phytoene synthase ( PSY ), zeta-carotene desaturase ( ZDS ), lycopene beta cyclase ( LCYB ), lycopene epsilon cyclase ( LCYE ), zeta-carotene isomerase ( ZISO ), carotenoid isomerase ( CRTISO ) and beta-carotene hydroxylase ( CHYB ) in eight developmental stages from peel of three Iranian pomegranate cultivars, Malas Isfahan (red-peel), Shirin Poost Sefid Saveh (white-peel) and Poost Siyah Yazd (black-peel) and its correlation with the amount of carotenoid. For this purpose, the RNA content was extracted from the peel of three pomegranate cultivars, using CTAB-based method and their cDNA was synthesized. Following the design of specific primers, the appropriate annealing temperature of each of them was determined by gradient PCR and the relative expression of the seven genes were evaluated by using real-time PCR. The total content of carotenoids was determined using a standard curve of ??-carotene in n-hexane: acetone (1:1). Significant difference in carotenoid content between the cultivars and developmental stages showed that the amount of carotenoid in pomegranate is influenced by cultivar and developmental stage. The carotenoid content was reduced during development. The highest carotenoid (169.36 ?g / g FW) was measured at the first stage of the white cultivar. Among the three cultivars from the first to fifth stages, the highest amount of carotenoid was related to the white cultivar and from sixth to eighth stages was measured in red cultivar. The highest amount of carotenoid was measured in Malas Isfahan followed by Shirin Poost Sefid Saveh and Poost Siyah Yazd. Expression of all investigated genes was influenced by the development stage. The cultivar had a significant effect on the relative expression of PSY , ZDS , LCYB , ZISO and CHYB genes. The effect of cultivar on the relative expression of LCYE and CRTISO genes was not significant. The highest expression of PSY , ZDS , LCYB , ZISO and CHYB genes was related to the red cultivar and the highest expression of CRTISO and LCYE genes was related to black cultivar. In black cultivar the maximum expression of LCYB , CHYB and CRTISO genes was detected in the fifth stage, and the highest expression of PSY , ZDS and ZISO genes was observed at the seventh stage. The highest expression in white cultivar was measured in isomerase genes of CRTISO and ZISO at the fifth stage and increased in the expression of PSY , LCYB and LCYE genes at the second stage. In red cultivar the highest expression of the all genes was measured in the seventh stage. Simultaneous expression of LCYB and LCYE genes in the late stages of development of the red cultivar and early stages in the white and black cultivars may indicate the production of (alpha) ?-carotene followed by lutein. However, in the early stages of the development of the red cultivar and the later stages in black and white cultivars, decreasing the expression of LCYE may be the path toward the beta-carotene. LCYB gene expression is complicated because of overlapping function with beta-carotene and alpha-carotene biosynthesis. The discrepancy between genes expression and carotenoid content can be attributed to the carotenoid antioxidant role in stress due to the inability to control environmental conditions and carotenoid degradation due to Carotenoids cleavage dioxygenases ( CCD ) activity. Key words Pomegranate, Carotenoid, Gene expression, qPCR.