Abstarct: Alpha-linolenic acid, as an important polyunsaturated fatty acid belongs to omega3 family, which is not produced in humans and, therefore, as a part of the diet should be taken into consideration to protect human health. Since The main source for this group of fatty acids is fish and because of environmental pollution, production of oilseed plants with the ability to produce high omega 3 fatty acids could provide a cheap and valuable source. The aim of this study is to clone Δ15desaturase gene in order to transfer oil plants to enhance the content of alpha-linolenic acid as a precursor to long-chain polyunsaturated fatty acids . In order to purification and amplification Delta 15 desaturase gene was reproduced, the total RNA was extracted and cDNA was synthesized from yeast pichia pastoris cells . Delta 15 desaturase gene amplification by PCR reaction with specific primers and the vector pTZ57R / T was cloned in E. coli bacteria. After selection of grown colonies on the selective medium containing the antibiotic ampicillin and coloning PCR, positive clones were selected. Digested by enzymes XbaI and SacI cutting and sequencing of cloned fragment, the existance of gene in cloning vector was confirmed. This gene construct was cloned in the recombinant vector containing pKS special Napin seed promoter was cloned. Enzymatic digestion with enzymes HindIII and SacI was performed the desired gene vector and the vector pBI121 was separated and then was cloned in E. coli bacteria. The grown Clones in selective medium containing the antibiotic kanamycin was selected and structural integrity delta-15 desaturase gene and promoter Napin was confirmed by performing colony PCR. The recombinant plasmid was transferred to Agrobacterium. After the contraction with Agrobacterium, for transformation of tobacco plants, the growning of explants of tobacco plants on selective medium containing different concentrations of kanamycin and cefotaxime approved their transformation. PCR with primers different transgenic tobacco plants also was confirmed in DNA level.