Abstract: In order to meet increasingly strict effluent TN discharge standards, a high efficient anaerobic denitrifier HK13 was isolated and purified with the modified bromothymol blue (BTB) medium from the anoxic activated sludge in a coal chemical wastewater treatment plant. Based on morphological observation and 16S rRNA gene sequence analysis, strain HK13 was identified as Pseudomonas stutzeri. The effects of carbon source, C/N ratio (carbon to nitrogen ratio), initial pH, dissolved oxygen (dissolved oxygen was characterized by shaker speed) and temperature on the denitrification characteristics of strain HK13 were studied using simulated nitrate wastewater, and the optimum growth conditions and the maximum nitrogen removal efficiency were determined. The results showed that: (1) The optimum denitrification conditions for strain HK13 were sodium citrate as the carbon source, C/N 8, 35 ℃, initial pH 8-10, and shaker speed 100 r/min. (2) Under the optimum conditions of initial ρ(NO₃^--N) of 106.67 mg/L, the TN removal efficiency of strain HK13 was 92.62% at 12 h. The peak TN removal rate of this strain reached 20.03 mg/(L·h) between 9 h and 12 h, and the TN removal efficiency was higher than 98% at 16 h without nitrite accumulation in the system. (3) The suitable temperature and pH range for strain HK13 were 20-40 ℃ and 7-10, respectively. These results demonstrated that strain HK13 exhibited efficient denitrification ability with alkalophilic feature, which broadened the environmental conditions of the biological denitrification process for the treatment of nitrogen polluted wastewater.