Abstract: Some strains having decoloration and degradation effects on reactive red PBLwere isolated from sludge from bioreactors of a dye factory. Through re-screening, one strain, named asTS4, was found to have a better decoloration performance and identified preliminarily asBacillus Sp. Experimental results show that the effect of decoloration is influenced by temperature, pH value and oxygen supply conditions. The optimum growth condition for the strain is 37℃, pH=7. 8 and sealed culture. In addition, this strain can endure the reactive red PBL to a concentration of200 mg/L, and the decoloration performance of a single strain isweaker thanmixed strains.