Through comparative anatomic, histopathologic, cytopathologic and epideminologic studies on the ill ( 14 Ind. ) and normal ( 1 Ind. ) farmed amour sturgeon, Acipenser schrenckii . No pathogenic microorganism was found. Outer symptom of earlier ill amour sturgeon was not obvious. Through anatomy hepat ic tissue degeneration was severely found. hepatic tissue was lipoid degeneration, watery degeneration and focal necrosis. Hepatic function changed from unusual to deterioration. The illness of encephalic liquefaction necrosis depend on the illness of hepatic tissue, encephalic cell was watery degeneration and necrosis, other organs t issues and cells was not found to be degeneration. Hepatic tissue degeneration was f irst, toxicopathy . encephalic liquefaction necrosis was secondary disease. The toxin that caused hepatic tissue degeneration came from the food. The cause of the illness and mechanism were also studied.