Chlorinated phenolic compounds are a class of toxic and refractory organic pollutants. The pollution caused by chlorophenols poses serious ecological and environmental problems. A stable bacterial consortium capable of reductively dechlorinating trichlorophenol was isolated using chlorophenol as the sole source of carbon and energy. The physiological characteristics of the mixed cultures were studied and the results show that the consortium could use pyruvate as the carbon and energy source. The fermentation of pyruvate, sulfate reduction and dechlorination process proceeded strictly in succession within this consortium. The effect of specific inhibitors on the dechlorinating activity of the consortium was investigated, and the results indicate that sulfate and molybdate (1 mmol/L) have a strong inhibitive influence on the dechlorination activity. Fluo-rescence in situ hybridization (FISH) technique was applied to analyzing the composition of the consortium and the results reveal that one major subpopulation within the consortium was phy-logenetically affiliated to gamma and delta subclass of Proteobacteria. Chlorinated phenolic compounds are a class of toxic and refractory organic pollutants. The pollution caused by chlorophenols poses serious ecological and environmental problems. A stable bacterial consortium capable of reductively dechlorinating trichlorophenol was isolated using chlorophenol as the sole source of carbon and energy. The physiological characteristics of the mixed cultures were studied and the results show that the consortium could use pyruvate as the carbon and energy source. The fermentation of pyruvate, sulfate reduction and dechlorination process proceeded strictly in succession within this consortium. The effect of specific inhibitors on the dechlorinating activity of the consortium was investigated, and the results that that sulfate and molybdate (1 mmol / L) have a strong inhibitive influence on the dechlorination activity. Fluo-rescence in situ hybridization (FISH) technique was applied to analyzing the composition of the consortium and the results reveal that one major subpopulation within the consortium was phy-logenetically affiliated to gamma and delta subclass of Proteobacteria.