In order to study the effect of different volumetric exchange rates (VER) on the granulation and stable operation of SNAD sludge, two lab-scale SBR reactors, with a 37.5% VER (R1) and 75% VER (R2), were comparably analyzed. Experimental results demonstrated that the granulation of R1 could be achieved in 36 days, was 12 days faster than R2. Meanwhile, a relatively lower sludge loss rate of R1 was obtained. The nitrogen removal rate (R_NR), R_AO and R_AN in R1 were 0.356 g·L^-1·d^-1, 0.113 0 and 0.080 9 g·g^-1·d^-1, respectively; while that of R2 was 0.248 g·L^-1·d^-1, 0.093 6 and 0.070 5 g·g^-1·d^-1, respectively. This confirmed that a lower VER reduced the loss of floc sludge, and further declined the granulation period. Moreover, a lower VER not only enhanced the activity of ammonia-oxidizing and anaerobic ammonia-oxidizing bacteria, but also suppressed nitrite-oxidizing bacteria, was benefit for a stable and efficient removal performance of the SNAD granular sludge.