Abstract: Using the static water test method,acute toxicity test of five common used disinfectants on juvenile Cyprinus carpio with full length of (4.73±0.82)cm was carried out at water temperature 26~28℃.The safe concentrations of five kinds of disinfectants were as follows:chlorine dioxide(4.960 mg/L),potassium permanganate(0.773 mg/L),bromochlorine(0.290 mg/L),trichloroisocyanuric acid(0.057 mg/L),and polyvidone iodine(0.071 mg/L),respectively.The order of their toxicities was trichloroisocyanuric acid > polyvidone iodine > bromochlorine > potassium permanganate > chlorine dioxide.