Walnut blight bacteria causes by Xanthomonas arboricola pv. juglandis is one of the most important disease in reducing the quantity and quality of the product in this plant. This study was conducted to evaluate sensitivity of some native walnut cultivars against Xanthomonas arboricola pv. juglandis. At first, the infected leaves and fruits of the nursery gardens were sampled and after transferring the samples to the laboratory, the isolation, biochemical and pathogenic tests were carried out. After DNA extraction and performing the PCR, the causative bacterial agent was detected with specific primers. The most violent bacterial isolates were selected for pathogenicity and evaluation of resistance or sensitivity of walnut cultivars. To study the interaction of bacteria with plant, a proteomic study was carried out. For this purpose, the leaves of four cultivars of walnut (Khosheii, Pecan, Chandler, Kaghazi) was inoculated with a most virulent isolate of Xanthomonas arboricola pv. juglandis in greenhouse conditions and samples were collected from bacterial symptoms. Protein was sampled from the aerial parts of walnut seedlings, and protein extraction was performed using TCA-Acetone method. For two-dimensional electrophoresis, in the first dimension, the IEF method and tube gels and the second dimension of SDS-PAGE were used. Coloring was carried out with Comassin Blue and was taken from the gels. Protein spots were compared with PD-Quest software and, using existing software, the level of protein spots displaying resistance and susceptibility was compared. As a result, two-dimensional electrophoresis of walnut leaves in the studied cultivars, based on induction factor (IF), resulted in the identification of 15 protein spots with significant changes in expression.