Abstract: Based on genomic database of the Japanese eel (Anguilla japonica), two types of lysozyme genes including one C-type and four G-type lysozyme genes were found and named as AJLysC, AJLysG1, AJLysG2, AJLysG3, and AJLysG4, which consisted of 809, 732, 1352, 1177 and 731 nucleotides that encode 143, 193, 185, 185 and 187 amino acids, respectively. AJLysC and AJLysG1 have 15 and 19 amino acids signal peptides, respectively, but other three lysozymes have no signal peptide. The gene structure of AJLysC, AJLysG2, AJLysG3 and AJLysG4 is similar to their corresponding lysozyme genes in other species in terms of exon-intron organization, with 4 exons for the C-type and 5 exons for the G-type. However, the gene structure of AJLysG1 differed from other fishes, with 6 exons, representing the first report in fish. Compared with other species, second catalytic residue, Asp, in AJLysG1 is missing. AJLysC shares high identity with C-type lysozymes of other species, having 72.7% identity with Japanese flounder (Paralichthys olivaceus). AJLysG2, AJLysG3 and AJLysG4 share high identity with each other and with those in other species, while AJLysG1 does not share high identity with neither G-type lysozymes of other species nor the other three, with the identity lower than 50%. The real-time quantitative PCR analysis showed that all five genes were expressed in all examined organs/tissues of eels. The C-type lysozyme gene expressed highly in stomach and modestly in immune related tissues. The expression of the four G-type lysozymes was tissue-dependent. AJLysG1 highly expressed in skin and muscle, while AJLysG2 highly expressed in blood, head kidney, trunk kidney and gills. All five genes were up-regulated in many organs/tissues by Edwardsiella tarda infection, especially in blood, intestine and head kidney. In addition, the recombinant proteins of AJLysG2, AJLysG3 and AJLysG4 obviously repressed the growth of Micrococcus lysodeikticus, however, their roles in inhibiting pathogenic bacteria of the Japanese eel need further investigation.