Abstract: The recombinant plasmid containing completed β-hemolysin gene of Aeromonas hydrophila was transformed into E.coli DH5α and could express β-hemolysin with native biological function.The ISCOMs included crude purified transformant’s extracellular products (ECPs) was made and named β-hemA-ISCOMs.The result showed it could enhanced the proliferation ability of eel’s lymphocyte and induced immunity significantly by oral administration (P0.05),after challenge,the livability of first immunized was 44.4%.the livability of second immunized was 100%.This was, to our knowledge,the first report about ISCOMs used in eel’s oral administration,indicated that ISCOMs technology could be widely used for producing fish oral vaccines.