Abstarct: Yellowing disease and vascular wilt are one of the most important disease of melon that Fusarium oxysporum f.sp. melonis fungu is the cause of the disease and in term of pathogenesis is classified in four strainzer 0,1, 2 and 1.2. Gene Fom2 as a resistance agent is known against zero and 1 strain of Fom fungus. In this study, due to the sensitivity of iranian melon cultivars against 1 strain, the presence of Fom2 gene as a resistance agent in genomic level were studied in cultivars such as Shiraz Shahd cantaloupe, Mashhadi melon, Khatun melon, Khaghani melon, Charentais Fom1 and Charentais Fom2. Fom2 gene sequence was retrieved from Gene Bank. And by doing bioinformatics analyzes determined the protected areas and were used for design of general primer (PSh20-F/R). The results of PCR with using primers (PSh20-F/R) confirmed the presence of Fom2 gene in studied cultivars and caused single band proliferation in expected size. Internal fragment of Fom2 gene was cloned for sequencing in pTG19 vector and by PCR colony technique with using internal primers of Fom2 gene and universal primers of PSh10.2-F/R was confirmed. Sequencing analysis revealed that susceptible varieties such as Mashhadi melon, Khaghani melon, Charentais Fom1 showed different nucleotide and protein diversity compared to resistant varieties that this diversity changed the protein structure of susceptible varieties and make them sensitive against zero and 1 strain. Identify different levels of resistance in cultivars is due to variation in gene sequence and protein exxpression levels of Fom2 gene.Then for complete sequence analysis of the gene Fom2 and the cloning specific primer pair (PSh20.2-F / R) was designed baxsed on the beginning and end of the gene. According to the resistance reported of Shiraz Shahd cantaloupe (M6), genome of this cultivar after DNA extraction was used as template. In electrophoretic pattern of the PCR product observed a single bandin size 3.3kb. After the fragment was cloned into the vector pTG19 and sequencing analysis the results showed the mutation in Shiraz Shahd cantaloupe cultivarhas no effect on function of Fom2 gene. In general the aim of cloned the fully complete fragmentin this study was Fom2 gene transfer into exxpression vector and after that transfer gene in to plant which in complementary studies will bestudied.