Abstract: The acute toxicities of three kinds of stimulating chemical, trichloroisocyanuric acid（TCCA）, potassium permanganate（KMnO4）, formaldehyde（HCHO）to juvenile Spinibarbus sinensis were studied through static and semi-static state processes. The results showed that trichloroisocyanuric acid was the most toxic to juvenile S. sinensis among the three kinds of stimulating chemical, potassium permanganate was the next, and the lowest toxic was formaldehyde. Their values of 96 h LC50 under static and semi-static state were 1.50, 1.13, 1.76, 1.24, 39.91, 36.72 mgL-1, respectively. Their safe concentration（SC） under static and semi-static state were 0.53, 0.34, 0.55, 0.39, 7.13, 6.77 mgL-1, respectively. The results indicated that although trichloroisocyanuric acid, potassium permanganate and formaldehyde have certain toxicity to juvenile S.sinensis, they can be applied in aquaculture as fishery drugs.