Abstract: In order to find out the optimum range of pH value for anammox reaction，simulated wastewater was used to study the effect of different pH，DO concentration on the performance of anammox reactor for Nitrogen removal in an ASBＲ reactor． And it is investigated that the effect of higher DO concentration on the performance of anaerobic ammonia oxidation sludge for nitrogen removal and the resistance capacity of anammox sludge against high DO concentration． The result shows that the optimum range of pH value for anaerobic ammonia oxidation reactor is 7. 5 ～ 8. 0，and its nitrogen removal performance is good and stable within this range: the removal rate of NH + 4 －N reached 90. 2%，and the NO － 2 －N removal rate reached 91. 1%． And anammox bacteria are very sensitive to oxygen content． There is significant inhibition effect when the DO in water is too high，but anaerobic ammonia oxidation reactor nitrogen removal efficiency can rapidly recovered when DO concentration being under control．