In order to evaluate the performance of a newly developed dynamic state membrane bio-reactor (MBR) with MIA, a full-scale plant with the capacity of 2 10 m(3)/d was operated for treating sewage. Due to the MIA, the effect of residual oxygen could be completely removed during the non-aeration period and recycle ratio could be reduced to 1 recycle-to-influent ratio. Even though the plant was operated in winter season, stable performance could be achieved (BOD, CODcr, SS, TN, TP and E. coli removal efficiency; 98.2, 95.2, 99.8, 72.7, 71.4 and 99.9%, respectively). Therefore newly developed dynamic state MBR with the MIA can be one of the useful biological nutrient removal (BNR) processes for stable nutrient removal.