The treatment of plants by herbicide glyphosate can affect their resistance to disease. The effect of glyphosate on the expression of pathogenesis-related and resistance genes in transgenic potato infected with two strains of late blight pathogen, Phytophthora infestans was investigated. To do so, an optimal concentration of glyphosate (1.8 mg/L) were been used on transgenic potato, Vesnianka cultivar. a high level of expression of pathogenesis-related genes (especially PR-2) and defense response genes (especially HSR-203j). In these plants, no signs of burn and infection were observed were observed in the potato leaves infected with pathogen, and treated by glyphosate. The results showed that treatment by glyphosate could help to induce the resistance to P. infestans by expressing genes encoding defense response proteins.