Langerhans cells, one of the subtypes of Dendritic cells, are mainly distributed in mammalian skin epidermis and some mucosal tissues, and play an important role in against bacterial infection. In order to study the structural characteristics of Langerhans cells and the effect of bacterial infection on the expression of gene-related the function of Langerhans cells, CD207 positive cells were detected in the head kidney and spleen of yellow catfish by immunohistochemistry, and the ultrastructure of Langerhans cells was further observed by transmissionSelectronSmicroscope. The results of real-time quantitative PCR showed that Edwardsiella ictaluri could induce significant up-regulation of gene-related the function of Langerhans cells in the immune organs of yellow catfish. The above results indicated that the structure of yellow catfish Langerhans cells was similar to that in other vertebrates and participate in the immune response induced by E.ictaluri. This study will not only help us analyze the evolutionary characteristics of Langerhans cells in vertebrates, but provides a theoretical basis for the research of the adaptive immune system of yellow catfish.