In order to optimize the processes for the collection of ISCOMs, and find the immunity of aerolysin and aerolysin ISCOMs.The aerolysin gene of Aeromonas hydrophila ZN1 was orientationally inserted into the prokaryotic expression Vector pET32a(+). The recombinant plasmid was transformed into E. coli BL21（DE3）. After being induced with 1mmol/L IPTG for 4h，the TrxAerolysin(Trx-AerA) fusion protein was expressed with inclusion bodies from and up to 65.5% in total recombined bacterial proteins. After being centrifuged at 40 000×g for 4 h，TrxAerolysin was divided into 5 groups for making ISCOMs: Group 1 was mixed with QuilA, Mega-10, lecithin,cholesterol,Group 2 was mixed with QuilA, Mega-10, Group 3 was mixed with QuilA,lecithin,cholesterol, Group 4 was mixed with QuilA, Group 5 only contained TrxAerolysin. All groups were centrifuged at 38 000×g for 20 h, centrifugal sedimentation was collected for analysis. After being analysed for protein concentration, SDS-PAGE and ultrastructure, the results showed that the protein yield rate of the five groups was 10.46%, 7.23%, 3.17%, 1.82%, and 0.53% respectively. The protein yield rate of the five groups had significant difference（P＜0.05），Mega-10, lecithin,cholesterol improved the yield rate of ISCOMs. Next, eels were divided into 4 groups for immunization. Group 1 was injected with Trx-AerA fusion protein ISCOMs, Group 2 was injected with Trx-AerA fusion proteins, Group 3 was injected with Trx ISCOMs, and Group 4 was injected with Tris-Cl. After 30 d, the immune effects were evaluated，five eels were selected from each group for the detection of the value of sera antibody while the others were challenged with Aeromonas hydrophilla ZN1. The results showed that the RPS of the eels immunized with Trx-AerA ISCOMs,Trx ISCOMs, Trx-AerA was 83.3%（13/15）,50%（9/15）,and 0（3/15）after being injected with 2.0×10⁶ CFU Aeromonas hydrophilla ZN1. The values of sera antibody to aerolysin during the group immunized with Trx-AerA ISCOMs and the group immunized with AerA were significantly higher than that of the group immunized with Trx ISCOMs（P＜0.05）. These results suggested that the nonspecific immune response might contribute greatly to eel immunity except in the case of sera antibody.