Currently, millions of people around the world for escaping the lethal effects of diabetes require constant injections of insulin. Thus, developing systems which can deacrease cost and frequency; are necessary. By the development of genetic engineering techniques, human insulin in bacteria E. coli and yeast were produced, but the production of recombinant proteins in microorganisms have some disadvantages such as high cost, the possibility of contamination with toxic proteins and costly purification steps, most research has been focused on the production of recombinant proteins in plants. In this study , enclosed structures containing pBI121 containing sequences Kozak , LTB, Extensin , Proinsulin human genes, and six amino acid histidine penetratin by Agrobacterium tumefaciens pv. LBA4404 meditation was transformed to tobacco plants. Gene presence in the genome of transgenic tobacco plants was confirmed by the PCR test. The results of RT-PCR reactions on human health attested proinsulin gene expression in transgenic tobacco. ELISA results showed that the transgenic plants have the ability to translate and produce the fusion protein of insulin, The produced insulin in plant tissues have been quite active and has potential applications in medicine. It seems that the estimated amount of recombinant protein produced in transgenic plants to (about 0/18 % of total proteins in transgenic plants) are suitable for the production of transgenic plants economically viable. Also, the presence and expression of the human Proinsulin in transgenic tobacco showed that the transformation of desired gene into the genome of tobacco plants was stable. Germination of first generation in growth medium containing kanamycin showed 3:1 ratio, this result attested Mendelian gene transfer of human Proinsulin in next generation of plants. Due to the positive results obtained from the construction of the project seems to have an ability to generate gene expression Proinsulin and transfer to other plants suitable for further investigation. Keywords : Diabetes, Proinsulin, Extensin, Penetratin, LTB.