Abstract: To study the pathogenesis of Salmonella enteritidis in experimentally infected ducks. Researchers used the immunohistochemical localization and histopathological to examine various tissues of ducks following oral infection were investigated. The time course for the appearance of viral antigen and tissue lesions in various tissues was coincidental. The study suggested that the bacteria levels of SE in systemic organs have a close correlation with the progression of disease. The abundance of target lamina propria and lymphoid cells may contribute to the high levels of bacteria infection and replication in lymphoid and intestinal tissues.