A bacterial strain R-2, capable of degrading fipronil, was isolated from a long-term fipronil-polluted activated sludge in a fipronil manufacture factory. Strain R-2 was preliminarily identified as Paracoccus sp. based on its physiological and biochemical properties, as well as the 16S rRNA gene sequence analysis. Strain R-2 could utilize fipronil as the sole carbon source for growth, and degrade 85% of 50 mg/L fipronil within 3 d in mineral salts medium. The optimal pH value and temperature for fipronil degradation by strain R-2 were 6.0?7.0 and 30 °C, respectively. The degrading rate showed a negative correlation with the initial concentration of fipronil. The addition of 0.1 mmol/L Zn2+ or Fe3+ to the culture medium could significantly increase the degradation of fipronil. In both sterile and non-sterile soils, strain could remove 63.4%?71.2% of 100 μg/g fipronil within 10 d.