Salmonella enterica includes several related serovars which have different host ranges and cause diseases of different severities. However, their pathogenic potential is unknown, and it is not clear what mechanisms are activated or inhibited during adaptation to a specific host environment. Some proteins are involved in the mechanism of pathogenicity at a molecular level and provide the functional aspects that create the diverse phenotypes. To compare proteomic analyses of the total proteins of Salmonella Enteriditis (SE), Typhimurium (ST), and Gallinarum (SG), two-dimensional gel electrophoresis (2-DGE) was performed using a pH 4-10 immobilized pH gradient (IPG) strip, and some proteins were identified by mass spectrometry (MS). After staining the gels, the proteins that were expressed at 10-fold or higher levels compared to other spots on the gel were characterized. Some of the identified proteins were related to virulence, such as β-lactamase, RfbH protein, and shikimate kinase. Additionally, there was a high level of variation between serovars despite the similarities in the expression patterns. Furthermore, this study shows that 2-DGE combined with MS is a useful tool for identifying proteins differentially expressed between serovars with different host ranges and pathogenic potential.