Abstract: An active desulfurizing strain of bacteria CTD843-T-3 was isolated from bio-active sludge collected in a wastewater treatment plant and loaded into a bio-trickling reactor for consecutive desulfurization of H₂S. When the reaction temperature was adjusted to 30℃, pH to 6.0,and the inlet concentration of H₂S to 500~3000 mg·m^-3,the H₂S removal rate of the strain could be kept over 92%, and the maximum H₂S loading rate could reach 6.5 g·m^-3·h^-1.Through the morphological, biochemical & physiological identification, and 16S rRNA sequence analysis, the strain was found to be ellipse-shaped, 0.4-0.6 μm in size,gram-negative,and a member of Pseudomonas.