An SBR reactor seeded with anaerobic granular sludge was started up to enrich deammonifition bacteria and investigate its nitrogen removal characteristics. Research results showed that deammonification granular sludge could be cultivated successfully with firstly enriched ANAMMOX microorganisms in anaerobic condition and then controlled the dissolved oxygen in the SBR reactor between 0.3 and 0.5 mg/L, in which the maximum total nitrogen removal rate reach 75.3%. When the Ca and P concentrations of the medium exceeded the necessary quantity, salt precipitation was observed and interfered with microbial activity and caused a decrease of the nitrogen removal rate of the reactor system. Salt precipitation was avoided by diminishing adequately the Ca and P concentrations of the medium during the following operation period, and the total nitrogen removal rate restored.