Potato cultivation has increased in Oman since 1989 as consumer demand for potato products has risen. Tuber moth (Phthorimaea operculella) insect is a serious constraint to the potato production in Oman. The emergence of Bacillus thuringiensis resistance in many economically important crops has gained the attention of many researchers. Transgenic plants expressing B.t genes in tissues have increased in popularity as the chosen form of pest control. B.t's derived gene expressing the endotoxin CrylAc was inserted into potato plant by (Agrobactirum. tumefaciens) in order to develop resistance against potato tuber moth (Phthorimaea operculella). The transgene (Cryl Ac) is expressed in all parts of the plant throughout the season whereas traditional insecticides lose their toxicity with time. The insecticidal proteins, 6-endotoxins expressed by Cry1Ac are specifically lethal to Lepidopteran insects. CrylAc coding sequences from B. thuringiensis has been constructed into Agrobacterium vectors plasmids (PRD400) and driven by double 35S CaMV promoter suitable for dicot transformation using kanamycin resistance gene as marker. Transgenic callus of potato has been grown on modified MS medium containing 500 mg/L carbenicilin and 300 mg/L kanamycin. DNA extraction, PCR amplification and ELISA, have verified the integration of CrylAc gene into potato genome. Bioassay of Potato tuber moth was tested in transgenic potato and mortality was found more than 80%.