This paper reported that a bacteria was isolated from the Mugic so--iug Basilewsky of hemorrhagic septicaemia and contirmed pathogenetic bacteria by artificial infection. The strain was abserved by morphological. TEM and this biochemical characteristics were also tested. According to Bergey’s Manual of systematic Bacteriology this isolate was identified as Aermouas hydrophlia. The major characteristics of this strain were rod-shaped body, Gram-negative, monopolar flagellum. The biochemical characteristics of the strain were that oxidizing enzyme and Catalase was positive; Vp test was negative; glucose were fermented but gum sugar were not done; His decarboxylase and Arg decarboxylase were negative et al. else.