In order to diagnose diseased rabbits, dead rabbits were dissected, and 4 strains, DX01, DX02, JX01 and JX02 were obtained from bacterial isolation and culture. According to conventional biochemical method, physiological-biochemical test showed that DX01 and DX02 could produce acids and gases in the presence of mannitol, lactose, glucose and maltose, and did not ferment sucrose, reactions of sodium citrate, urea, V-P, hydrogen sulfide and gelatin were negative, while reactions of indole, M-R and nitrate were positive, which were in accordance with the characteristics of colibacillus; and JX01 and JX02 both fermented mannitol, sucrose, glucose, maltose, and did not ferment lactose, reactions of indole, M-R, V-P, hydrogen sulfide and gelatin were negative, while the reaction of nitrate was positive, which were in accordance with the characteristics of Pasteurella. 16S rDNA detection and sequencing showed that JX01 and JX02 shared 100% homology with Pas- teurella. The animal inoculation test of isolated bacteria showed that the mice in the experiment groups all died within 2 d. Original cultures were isolated from dead mice. DX01 and DX02 were identified as colibacillus, JX01 and JX02 were identified as Pasteurella, and the death of diseased rabbits was caused by mixed infection of pasteureUosis and colibacillosis. Drug sensitive test showed that DX01 and DX02 were only sensitive to kanamycin, ofloxacin and sulfamethoxydiazine, and not sensitive to other drugs, and JX01 and JX02 were sensitive to ofloxacin, sulfamethoxydiazine, gentamicin, furazolidone, doxycycline, streptomycin, trimoxazole and spectinomycin, and were moderately sensitive to cefradine. Ofloxacin and sulfamethoxydiazine are preferable for the clinical treatment of this disease.