This work evaluates the efficiency of ammonium removal from piggery wastewater using a sequencing batch reactor (SBR) inoculated with a newly isolated strain of Pseudomonas putida HJH1. The strain HJH1 not only could survive and remove up to 72.4 mg/L NO₂^--N under aerobic conditions, but it also has good performance for simultaneous nitrification and denitrification (SND) with no nitrite accumulation. The SBR system was able to consistently remove: 1) 76.4-100% ammonium nitrogen and 71.4-100% COD from artificial wastewater in stage 1, and 2) 89.2-99.1% ammonium nitrogen and 82.4-100% COD from piggery wastewater in stage 2. During the whole operation, the strain HJH1 predominated in the SBR all the time to function together with other bacteria. Results indicated that the SBR system inoculated with Pseudomonas putida HJH1 can efficiently remove ammonium nitrogen from piggery wastewater, thereby having potential applications for future nitrogen removal.