Inactivated whole -cell and cell chemical components were prepared with Aeromonas hydrophila Ah961004 ,Ah960916 ,Ah970516 and A .sobria As970510 ,Soft shell turtles , Trinyx sinensis ,were immunized via intramuscular route , after 15d booster doses , challenged with strain Ah961004 intraperitoneally and observed for 20d , The results showed that the group of A .sobria As970510 inactivated whole -cell with its extracellular products and the group of A .hydrophila Ah961004 outer membrane components had highly protection against strain Ah961004 , with the protection rate 87 .5 % and 75 % respectively , the other groups were lower than 50 %.