Anaerobic bacterium (strain SN9) with simultaneous capabilities of denitrification and sulfate reduction was enriched and isolated in a specially designed medium by anaerobic Hungate technology. The characterization of SN9 was conducted from the morphological, physiological and phylogenetic aspects. It was a rod-shaped, gram-negative, 0.2-0.8 µm in width and 2.0-5.0 µm in length. Most of the fatty acids of SN9 distributed among C_12:0~C_19-CYC-FAME and the main fatty acids consisted of C_{14:0 FAME}, C_16:0-FAME, C_18:1c-FAME,C_18:0-FAME,C_19-CYC-FAME. Based on the morphological and physiological characteristics as well as the phylogenetic analysis, SN9 was identified as Bacillus coagulans since its 16S rDNA beared 99% resemblance to that of Paenibacillus lautus SN9 (Accession No. DQ450463). The removal efficiencies of NO₃^– and SO₄^2- were up to 80.78% and 96.22 % when the initial concentrations of NO₃^– and SO₄^2- were 3812.59 mg/L and 552.52 mg/L, respectively. The characterization of the present isolate had important ecological implications in treating organic wastewater containing high concentration of sulfate and nitrogen.