Bromoxynil is an antidicot herbicide widely used on cereal crops and has a short half life in the soil. A bxn gene, encoding a specific nitrilase that converts bromoxynil to its primary metabolite 3,5-dibromo-4- hydroxybenzoic acid, was inserted in plant binary vector pGA482, and then introduced into tobacco and lettuce plants via Agrobacterium mediated leaf-disc transformation method. Transgenic plants with the bxn gene were selected by kanamycin and regenerated to whole plants. The regenerated transgenic plants were determined level of expression of bxn gene by Northern blot analysis. The regenerated plants were tested for herbicide resistance under the presence of several concentrations of bromoxynil.