Abstract: The treatment of simulated wastewater containing high-concentration (up to 700 mg/L) ammonia nitrogen with heterotrophic nitrification-aerobic strains in Sequencing Batch Reactor (SBR) was studied. Four influencing factors of SBR including the temperature, dissolved oxygen concentration, pH and hydraulic retention time were studied and the optimal operating conditions obtained. The results indicated that the efficiency of simultaneous nitrification and denitrification by seeding sludge and dominant bacteria could be enhanced after cultured for forty-five operational cycles in SBR. Under the optimal conditions of temperature 23~25 ℃, dissolved oxygen concentration 2 mg/L, pH 6.8-8.0 and hydraulic retention time 78 h, when the chemical oxygen demand was 2 500 mg/L and the ammonia nitrogen was 700 mg/L in the influent, the chemical oxygen demand removal efficiency could reach 88%-93%, while the ammonia nitrogen and total nitrogen removal efficiency could achieve as high as 98%~99% and 86%-93% respectively.