Pyridine could be successfully removed in the polyurethane(PU) biofilter inoculated with activated sludge treating industrial wastewater. The elimination capacity for pyridine in the PU biofilter was approximately 27 g m⁻³ h⁻¹ at the tested loading range, The pH value of drainage was increased due to the accumulation of ammonia which was one of the metabolites of pyridine, Four pyridine-degrading bacteria were isolated from the PU biofilter, and they were closely related with Rhodococcus pyridinivorans(98~99% similarity). The specific growth rate of the isolate in the medium supplemented with pyridine as a sole carbon and energy source were ranged from 0.038 h⁻¹ to 0.051 h⁻¹.