Objective: Identity the genetic aspects and major gene influence on energy balance, milk production, fertility, food safety and consumer are the recent interests of genetic and breeding researchers.Methods: Najdi Cattle is the most prominent breeds in Khuzestan province. To do this plan in Shoushtar Najdi Cattle Station, blood samples were taken from 15 Najdi Cattles. DNA was extracted from whole blood using the method of Boom et al and polymerase chain reaction took for amplification of two fragments 544 bp and 566 bp. After ensuring the accuracy of the duplicated sequences on 1% agarose gel, sequencing was performed and the Leptin gene promoter components pointed out in Najdi Cattle. In this study, the six mutations identified in the first fragment 566 bp. In these mutations, 2 types of them were point mutations including Transition and Transversion, and 4 mutations were Frame shift which included Deletion (3kinds) and Insertion (1kind). In the second fragment 544 bp, 2 point mutations (transition and Transversion) and 1 Frame shift mutation (deletion) were appeared, in the Leptin gene pro-motor region. Also, in this study, the sequences related to each sample was compared in the two fragments in the aspect of similarity with other documented sequences, that BLAST results showed that high percentage of similarity.Results: According to the obtained results, it could be said that the sequence of leptin gene of Najdi cattle in Khuzestan province is similar to other documented sequences and there are a high-similarity percentage between current samples’ sequences and those documented in global information bank.