Abstract: In order to determine the pathogenic factors of Rex rabbit in Nanchang rabbit farm and to find effective prevention and control measures, the experiment carried out clinical diagnosis, bacterial isolation, biochemical identification, 16 S rRNA molecular biology identification, drug sensitivity test, in vitro antibacterial test and animal regression test on dead Rex rabbits. The results show that there were needle-shaped white necrotic spots on the liver on autopsy and Wright’s staining microscopic examination showed two-pole dense staining. The colony showed roundness and non-hemolysis on 5% rabbit blood agar medium, and it was Gram-negative short bacillus. The isolated bacteria can ferment sucrose, but not lactose. The methyl red and acetyl methyl methanol tests were negative. Agarose gel electrophoresis obtained a band of 1 800 bp in size, and the homology between the isolate and Pasteurella in NCBI was as high as 97.3%-100%. The isolate was highly sensitive to ceftriaxone, and was resistant to acetylspiramycin and ampicillin. Ligilactobacillus salivarius had good inhibitory effect on the isolate. The isolate was highly pathogenic, and all mice died within 12 hours after the challenge. The results suggested that the isolate was Pasteurella,and ceftriaxone or cephalexin were the first choice for prevention and treatment.