Abstract: The acute toxicity including median lethal concentration（LC50） and the safe concentration of seven kinds of disinfectants to hybrid sturgeon（Acipenser baeri♂ × A.schrenkii ♀） juveniles with body weight of 12.2±0.7 g was studied in a 90 cm×60 cm×30 cm tank at water temperature of 22-24 ℃.The sensitivity rank of the hybrid sturgeon to the drugs was found to be arranged as the following：trichloroisocyanuric acid powder chloramine T povidone lodine solution chlorine dioxide formalin oxytetracycline hydrochloride sodium chloride.The safe concentration was found 0.21 mg/L for trichloroisocyanuric acid powder,2.59 mg/L for chloramine T,3.88 mg/L for povidone lodine solution,6.35 mg/L for chlorine dioxide,9.86 mg/L for formalin,143.45 mg/L for oxytetracycline hydrochloride,and 2396.03 mg/L for sodium chloride.It was found that the povidone lodine solution,chlorine dioxide,formalin and sodium chloride were better choices for hybrid sturgeon＇s disinfection,while trichloroisocyanuric acid powder and oxytetracycline hydrochloride have a special sensitivity to the hybrid sturgeon juveniles,whose disinfection concentration was lower than that in conventional cultured fish.Since the toxicity of chloramine T was found to be closely related with the water pH value,more attention should be paid to the pH value in the water in which the chloramine T is administrated.

Key words: hybrid sturgeon, sensitivity, Chloramine-T, safe concentration