To identify the pathogen of rotting body disease in hybrid sturgeon(Acipenser baerii♀ × Acipenser schrenckii♂) in Zixing City, Hunan Province, a dominant strain of ABSW-1 was isolated from diseased sturgeon, and was subjected to morphology, physiological and biochemical characterization, 16S rDNA sequence analysis, virulence gene detection, regression infection, and antibiotic drug sensitivity tests. The results showed that sturgeon suffering from rotting body disease showed white ulceration on the body surface, white spots on the kidney, enlarged cellular gaps in the kidney, obvious atrophy of the glomeruli, and damage to the monolayer cuboidal epithelial cells of some of the renal tubules, and atrophy of their structures. The isolated dominant bacterium, ABSW-1, was identified as a gram-negative short bacterium with a monopolar flagellum. The bacterium was highly correlated and clustered into a single unit with the standard strain of Aeromonas veronii (MK990549.1) with a confidence level of 100%. The physiological and biochemical responses of strain ABSW-1 was essentially identical to those of the Aeromonas veronii standard strain. Strain ABSW-1 carried a total of six virulence genes, i.e., act, hly, aer, ompa, aha and alt. At a water temperature of (24±1) ℃, the mortality rate of the experimental group was significantly increased compared with that of the control group. Strain ABSW-1 exhibited resistance to ampicillin, vancomycin, erythromycin, cefathiophene and penicillin, but was highly sensitive to tetracycline, gentamicin, enrofloxacin, florfenicol and chloramphenicol. In summary, strain ABSW-1 may be the causative agent of rotting body disease in hybrid sturgeon, which has high pathogenicity and can trigger lesions in several organs of hybrid sturgeon.